A Brief History of High-Energy (X-ray & Gamma-Ray) Astronomy

We list here (in reverse chronological order, notice) many important events in the history of astronomy, particularly high-energy astronomy (X-ray astronomy, gamma-ray astronomy and cosmic-ray astronomy), with particular emphasis on events concerning space-based observatories with X-ray and gamma-ray detectors on board which observed cosmic (i.e., non-solar) sources. (Some of the major events in planetary exploration missions are listed, but for a comprehensive chronology, see the NSSDC Chronology of Lunar and Planetary Exploration).

Also available:

A graphical version of the dates of operation of high-energy astrophysics missions,
some common questions (and their answers!) about high-energy astronomy, and
a review paper on X-ray astronomy missions up to the early 1990s.

For more detailed information on NASA's possible future astrophysics and physics missions, see the NASA Astrophysics website.

For more on the history of NASA, see the NASA History Office website.

Index by Year Range

BCE (BC) 1 - 999 CE (AD) 1000 - 1499 CE (AD) 1500 - 1599 CE (AD) 1600 - 1699 CE (AD)
1700 - 1799 CE (AD) 1800 - 1899 CE (AD) 1900 - 1959 CE (AD) 1960 - 1964 CE (AD) 1965 - 1969 CE (AD)
1970 - 1974 CE (AD) 1975 - 1979 CE (AD) 1980 - 1984 CE (AD) 1985 - 1989 CE (AD) 1990 - 1994 CE (AD)
1995 - 1999 CE (AD) 2000 - 2004 CE (AD) 2005 - 2009 CE (AD) 2010 - 2014 CE (AD) 2015 - 2019 CE (AD)
2020 - 2024 CE (AD) 2025 - 2029 CE (AD) 2030 - 2034 CE (AD) 2035 - 2039 CE (AD)



2034 Possible launch of the proposed Laser Interferometer Space Antenna (LISA) mission. In 2013, ESA selected 'The Gravitational Universe' as the theme for its third Large-class mission (L3) in ESA's "Cosmic Vision 2015-25" program in which it committed to launch a space-based gravitational wave observatory in the early 2030s. In January 2017, LISA was proposed as the candidate mission. On June 20, 2017 LISA was formally approved as one of the main research missions of ESA. LISA will consist of three spacecraft flying 5 million kilometers (km) apart in the shape of an equilateral triangle. The center of the triangle formation will be in the ecliptic plane 1 AU (150 million km) from the Sun and 20 degrees behind the Earth. The main objective of the LISA mission is to observe gravitational waves from galactic and extra-galactic binary systems, including gravitational waves generated in the vicinity of the very massive black holes found in the centers of many galaxies. Gravitational waves are one of the fundamental building blocks of our theoretical picture of the universe. Although there already was strong indirect evidence for the existence of gravitational waves, they were not directly detected until 2015, when LIGO detected a "chirp" of gravitational waves from the merger of two ~30 solar mass black holes (see the item below dated 2016 Feb 11, the date that this discovery was made public). The three LISA spacecraft flying in formation will act as a giant Michelson interferometer, measuring the distortion of space caused by passing gravitational waves. Each spacecraft will contain two free-floating 'proof masses'. The proof masses will define optical paths 5 million km long, with a 60 degree angle between them. Lasers in each spacecraft will be used to measure changes in the optical path lengths with a precision of 20 picometers (1 pm = 1 trillionth of a meter).


2028 Possible launch of the Advanced Telescope for High-Energy Astrophysics (Athena), the second Large-class mission (L2) in ESA's "Cosmic Vision 2015-25" program. This mission is an X-ray observatory which will be designed to address key questions in astrophysics, including: "How and why does ordinary matter assemble into the galaxies and galactic clusters that we see today?" and "How do black holes grow and influence their surroundings?". Its instrumentation will include the largest X-ray mirror ever flown (effective area of 2 square meters at 1 keV and 0.25 square meters at 6 keV, with 5 arcsec angular resolution), plus two selectable focal plane detectors: a Wide Field Imager (WFI) (active pixel sensor with 40 arcmin field of view) and an X-ray Inertial Field Unit (X-ray calorimeter with 2.5 eV spectral resolution and 5 arcmin field of view). It will be placed into an L2 halo orbit and have a nominal five-year lifetime.
2025 Possible launch of the enhanced X-ray Timing and Polarimetry mission (eXTP), a science mission designed to study the state of matter under extreme conditions of density, gravity and magnetism. The eXTP international consortium includes major institutions of the Chinese Academy of Sciences and universities in China, as well as major institutions in several European countries and other international partners. eXTP's primary goals are the determination of the equation of state of matter at supra-nuclear density, the measurement of QED effects in highly magnetized star, and the study of accretion in the strong-field regime of gravity. Primary targets include isolated and binary neutron stars, strong magnetic field systems like magnetars, and stellar-mass and supermassive black holes. The mission will carry a unique and unprecedented suite of state-of-the-art scientific instruments enabling for the first time ever the simultaneous spectral-timing-polarimetry studies of cosmic sources in the energy range from 0.5-30 keV (and beyond).


Mid-2020's Possible launch of the Wide-Field Infrared Survey Telescope (WFIRST) observatory, the revised and expanded concept which the 2010 NASA Astrophysics Decadal Survey recommended to replace the Joint Dark Energy Mission (JDEM), as part of NASA's Physics of the Cosmos Program. WFIRST will "cast light" on dark energy by studying baryon acoustic oscillations, weak gravitational lensing and Type Ia supernovae using large-area spectroscopic and photometric surveys. It will also study exoplanets using microlensing techniques. It will have a 2.4-m telescope and two primary instruments, a wide-field instrument capable of both imaging and spectroscopy in the 0.6-2.0 μm range whose sharp point-spread function will provide precision photometry and stable observations for implementing the Dark Energy, Exoplanet Microlensing, and NIR surveys goals of the mission, and a coronagraph operating in the 0.43-0.98 μm range with both an imaging and a spectroscopic mode that is designed to perform exoplanet direct imaging and spectroscopic characterization of planets and debris disks around nearby stars.
2021 March 30 Projected launch on an Ariane 5 rocket from French Guiana of the James Webb Space Telescope (JWST). This NASA/ESA/Canadian Space Agency mission comprises a large infrared telescope with a 6.5 meter diameter primary mirror, and will study, e.g., the first generation of galaxies that formed in the early Universe, stars forming planetary systems, the atmospheres of nearby exoplanets outside our solar system, objects within our solar system, among many other research topics. JWST's instruments will observe at wavelengths from the optical (0.6 microns) to the mid-infrared (29 microns). JWST will, like WMAP, be placed in an orbit around the Sun-Earth Lagrange point L2 which is located 1.5 million km from the Earth in the anti-Sun direction.
2020 or 2021 Projected launch on a Soyuz ST 2-1b rocket of the Euclid observatory, a European Space Agency mission with important contributions from NASA, including infrared detectors for one instrument and science and data analysis. Euclid will "map the geometry of the dark Universe" using wide-field, high-spatial-resolution optical and infrared cameras. According to ESA, once the mission reaches its target orbit around the Sun-Earth Lagrange point L2, it will investigate the distance-redshift relationship and the evolution of cosmic structures by measuring shapes and redshifts of galaxies and clusters of galaxies out to redshifts ~ 2, or equivalently to a look-back time of 10 billion years. In this way, Euclid will cover the entire period over which dark energy played a significant role in accelerating the expansion. Euclid is optimised for two primary cosmological probes:
Weak gravitational Lensing: Weak lensing is a method to map the dark matter and measure dark energy by measuring the distortions of galaxy images by mass inhomogeneities along the line-of-sight;
Baryonic Acoustic Oscillations (BAOs): BAOs are wiggle patterns, imprinted in the clustering of galaxies, which provide a standard ruler to measure dark energy and the expansion in the Universe.


2019 July 13, 8:31am EDT Launch of the Russian Space Agency's Spectrum-R(oentgen)-Gamma orbiting X-ray observatory. This mission, a totally reconfigured version of what was once called Spectrum-X-Gamma, has a science payload which includes the following X-ray instruments:
- extended Roentgen Survey with an Imaging Telescope Array (e-ROSITA): Germany
- Astronomical Roentgen Telescope X-ray Concentrator (ART-XC): Russia
eROSITA will perform an all-sky medium-energy X-ray survey with a hundred times more sensitivity and a hundred times better angular resolution than the best previous 2-10 keV survey (performed by the A-2 instrument on HEA0-1 in the late 1970's). The main scientific goals are:
* To detect systematically all obscured accreting Black Holes in nearby galaxies, as well as many (~ 3 Million) new, distant active galactic nuclei,
* To detect the hot intergalactic medium of 50-100 thousand galaxy clusters and groups and hot gas in filaments between clusters, so as to map out the large-scale structure in the Universe for the study of cosmic structure evolution, and
* To study in detail the physics of galactic X-ray source populations, like pre-main sequence stars, supernova remnants and X-ray binaries.
2018 Aug 12, 3:31am EDT Launch of the Parker Solar Probe (PSP), a mission to the nearest star, the Sun. The probe "will swoop to within 4 million miles of the sun's surface, facing heat and radiation like no spacecraft before it. [It] will provide new data on solar activity and make critical contributions to our ability to forecast major space-weather events that impact life on Earth". The Parker Solar Probe has three detailed science objectives:
To trace the flow of energy that heats and accelerates the solar corona and solar wind,
To determine the structure and dynamics of the plasma and magnetic fields at the sources of the solar wind,
To explore the mechanisms that accelerate and transport energetic particles.
2018 Apr 30, 10:45am EDT Re-entry and destruction in the Earth's atmosphere of the Rossi X-ray Timing Explorer (RXTE), a NASA mission that was designed to facilitate the study of time variability in the emission of X-ray sources with moderate spectral resolution. Time scales from microseconds to months were covered in RXTE's broad spectral range from 2 to 250 keV. It was designed for a required lifetime of two years, but actually operated for more than 16 years from 1995 Dec 30 to 5 Jan 2012. Despite its fiery demise, RXTE left a large legacy of science results. The archive of RXTE data is still available to be utilized at the HEASARC.
2018 Apr 18, 6:51 pm EDT Launch of the Transiting Exoplanet Survey Satellite (TESS). This NASA mission will discover thousands of exoplanets in orbit around the brightest stars in the sky. In a two-year survey of the solar neighborhood, TESS will monitor more than 200,000 stars for temporary drops in brightness caused by planetary transits. This first-ever spaceborne all-sky transit survey will identify planets ranging from Earth-sized to gas giants, around a wide range of stellar types and orbital distances. No ground-based survey can achieve this feat, and the previous NASA planet-finding mission, Kepler, performed a pencil-beam survey, looking deeply at a single patch of sky. While this type of survey was ideal for carrying out the census of the frequency of planets that has proved so successful, the scientific focus of TESS will be to find planets around bright, nearby stars. These planets will be well-suited for follow-up observations and characterization with both ground-based facilities and missions such as Hubble and JWST.
2018 Mar 14 Death of Stephen Hawking (1942-2018), one of the leading cosmologists and popularizers of astronomy in the last century. Hawking's achievements were made all the more remarkable by the fact that he developed ALS (amyotrophic lateral sclerosis) in his early twenties. His research on black holes and on the interaction between quantum mechanics and general relativity was a seminal contribution to the field.
2017 Dec 06 A new contender for the most distant quasar ever seen in the Universe, ULAS J134208.10+092838.61, is announced by Bañados et al. (2018, Nature, 553, 473), with a measured redshift of 7.54, significantly more than the previous record-holder (ULAS J1120+0641, with a redshift of a mere 7.09). According to the authors, "the existence of this supermassive black hole when the Universe was only 690 million years old, just five per cent of its current age, reinforces early models of black hole growth that allow black holes with initial masses of more than about 104 solar masses or episodic hyper-Eddington accretion".
2017 Nov 15 The sixth transient gravitational wave detection, GW 170608 is announced by the LIGO Scientific and Virgo Collaborations. The waveform of the event detected on June 8th, 2017 at 02:01:16.5 UT was consistent with that predicted from the merger of two black holes of roughly 7 and 12 solar masses into a single black hole of 18 solar masses, meaning that energy equivalent to about 1 solar mass was emitted as gravitational waves during the collision. GW170608 is the lightest black hole binary merger that LIGO and Virgo have yet observed and so "is one of the first cases where black holes detected through gravitational waves have masses similar to black holes detected indirectly via electromagnetic radiation, such as X-rays". See Abbott et al. (2017, ApJL, submitted) for more details on this merger event.
2017 Oct 16 The fifth transient gravitational wave detection, GW 170817 is announced by the LIGO Scientific Collaboration and the Virgo collaboration. This is the first detection of gravitational waves from the merger of neutron stars, as opposed to black holes. The waveform of the event detected on August 17th, 2017 at 08:41 EDT was consistent with that predicted from the merger of two neutron stars of roughly 1.6 and 1.1 solar masses into a single object, either a massive neutron star or (more likely) a "low-mass" black hole. Just 1.7 seconds after the GW detection, the Fermi GBM and INTEGRAL gamma-ray observatories detected a short gamma-ray burst (GRB 170817A), and follow-up multi-wavelength electro-magnetic (gamma-ray, X-ray, UV, optical, IR and radio) observations by 70 space- and ground-based telescopes over the next days and weeks pinpointed the counterpart object to be a so-called kilonova or r-process supernova in the elliptical galaxy NGC 4993. Among other ramifications, (1) the near-simultaneity of the GW and em signals confirmed that they both travel at the speed of light as predicted by Genefral Relativity, (2) the association with NGC 4993 and the properties of the GW signal provide a direct measurement of the Hubble Constant of 70 (+12, -8) km/s/Mpc that is completely consistent with that measured by the Planck mission (67.90 +/- 0.55 km/s/Mpc), and (3) the evolution of the optical and infared emission of the source over the first week or so is "dominated by the radioactive glow (known as a "kilonova") from freshly synthesized rapid neutron capture (r-process) material in the merger ejecta" (Troja et al. 2017, Nature, in press), consistent with the theoretical predictions that such events have produced most of the heavy elements (such as gold, platinum and uranium) in the Universe.
See the LIGO press release, the GW discovery paper by Abbott et al. (2017, PRL, 119, 161101) and this issue of Astrophysical Journal Letters containing more than 20 papers about the multi-wavelength follow-up observations for more details on this merger event.
2017 Oct 3 Rainer Weiss, Barry C. Barish and Kip S. Thorne are awarded the 2017 Nobel Prize in physics for their major contributions to the LIGO detector and the observations of black hole merger events that create enormous "chirps" of gravitational waves. Just 6 days previous to this announcement, the LIGO Scientific and Virgo collaborations reported the fourth such gravitational wave detection.
2017 Sep 27 The fourth transient gravitational wave detection, GW 170814 is announced by the LIGO Scientific Collaboration and the Virgo collaboration. This is the first joint detection of gravitational waves by both LIGO and Virgo detectors, and as a result has by far the best localization (60 square degrees) on the sky of the 4 GW detections. The waveform of the event detected on August 14th, 2017 was (like the previous three gravitational wave source detections, GW 151226, GW 150914 and GW170104) consistent with that predicted from the merger of two black holes into a single, more massive, spinning black hole. The masses of the merging black holes in this third confirmed event were 31 and 25 solar masses, and the mass of the final black hole is 53 solar masses, with the "missing" 3 solar masses having been converted into gravitational waves. See Abbott et al. (2017, PRL, in press) for more details on this merger event.
2017 Sep 15, 7:55 am EDT Loss of contact with and subsequent destruction of the Cassini spacecraft as it was deliberately plunged into the atmosphere of Saturn. This was done by NASA so as to avoid Cassini (at some future time when it was no longer controllable) colliding with and possibly contaminating any of Saturn's moons, particularly Europa, with hitchhiking terrestrial microbes that the spacecraft may be carrying. Cassini was launched in 1997, and arrived at Saturn in 2004, whence it has beamed back a vast amount of ground-breaking information about Saturn, its moons and its ring system, not the least of which is breath-taking imagery. "This is the final chapter of an amazing mission, but it's also a new beginning", said Thomas Zurbuchen, associate administrator for NASA's Science Mission Directorate at NASA Headquarters in Washington. "Cassini's discovery of ocean worlds at Titan and Enceladus changed everything, shaking our views to the core about surprising places to search for potential life beyond Earth". Rest easy, Cassini!
2017 Aug 14, 12:31 pm EDT Launch on a SpaceX Dragon spacecraft of the ISS-CREAM (International Space Station Cosmic Ray Energetics And Mass) payload that will be subsequently attached robotically to the International Space Station and, starting in Fall 2017, will be used to to extend the energy reach of direct measurements of cosmic rays to the highest energy possible to probe their origin, acceleration and propagation. ISS-CREAM, a collaboration of US, Korean, French and Mexican institutions, will (1) determine how the observed spectral differences of protons and heavier nuclei evolve at higher energies approaching the knee; (2) be capable of measuring potential changes in the spectra of secondary nuclei resulting from interactions of primary cosmic rays with the interstellar medium; (3) conduct a sensitive search for spectral features, such as a bend in proton and helium spectra; and (4) measure electrons with sufficient accuracy and statistics to determine whether or not a nearby cosmic-ray source exists. It will also contribute indirectly to the dark matter search by measuring electrons in addition to nuclei at energies beyond where current direct measurements exist.
2017 Jun 30 Mission completion for the ESA (with NASA participation) LISA Pathfinder (LPF) mission. After sixteen months of science operations, LISA Pathfinder successfully demonstrated the technology that will be required for ESA's future space observatory of gravitational waves, the Laser Interferometer Space Antenna (LISA). This latter mission will consist of a "constellation" of 3 spacecraft that are currently planned to be launched in 2034. LISA will study the low-frequency (0.1 mHz to 1 Hz) gravitational waves produced by the mergers of supermassive black holes sitting at the centers of galaxies. LPF demonstrated a precision in the 60 mHz to 1 Hz range that surpasses the level required by LISA by a factor of more than 100 (!), and a precision in the 0.1 mHz to 60 mHz range that is within a factor of several of meeting LISA's requirements. See Armano et al. 2016, PRL, 116, 231101 for the initial results from LPF.
2017 Jun 15, 03:00 UTC Launch of the Chinese Hard X-ray Modulation Telescope (HXMT, now renamed to Huiyan or "Insight") mission on a Long March 4B rocket from the Jiuquan Satellite Launch Center. This observatory will perform the most sensitive all-sky survey to date in the hard X-ray (20 - 250 keV) energy band. It will also have soft and medium X-ray (1 - 30 keV) detectors for pointed observations of such objects as X-ray binary systems containing black holes or neutron stars, active galactic nuclei (AGN), supernova remnants, soft gamma repeaters (SGRs), and clusters of galaxies.
2017 Jun 3, 05:07pm EDT Launch on a SpaceX Dragon spacecraft of the Neutron Star Interior Composition ExploreR (NICER), a NASA Explorer Mission of Opportunity that was subsequently attached robotically to the International Space Station and, starting in mid-July 2017, will be used to study the soft X-rays emitted by neutron stars and other X-ray sources, such as ultraluminous X-ray sources (ULXs) and active galactic nuclei (AGN). NICER will have a timing resolution far beyond the capabilities of any X-ray observatory flown to date, and a sensitivity significantly better than XMM-Newton, which should enable it, inter alia, to accurately measure pulsar radii. This latter ability should allow it to rule out most of the competing, still currently viable, mass-radii relations/equations of state for the ultradense matter of which pulsars are composed, e.g., neutronized matter vs. "quark soup". This mission will also explore the feasibility of X-ray navigation (XNAV) and X-ray communications (XCOM) through its Station Explorer for X-Ray Timing and Navigation (SEXTANT) component, with potential applications for outer solar system missions.
2017 Jun 1 At a press conference, it is announced that the Laser Interferometer Gravitational-wave Observatory (LIGO) has detected a third transient gravitational wave source, GW 170104. The waveform of this event detected on January 4th, 2017 was (like the previous two gravitational wave sources GW 151226 and GW 150914) consistent with that predicted to be produced by the merger of two black holes into a single, more massive, spinning black hole. The masses of the merging black holes in this third confirmed event were 32 and 19 solar masses, and the mass of the final black hole is 49 solar masses, with the "missing" 2 solar masses having been converted into gravitational waves. This most recent detection appears to be the farthest yet, with the black holes located about 3 billion light-years away. See Abbott et al. (2017, PRL, 118, 21101) for more details on this tremendously energetic merger event.
2016 Sep 20 Victor Buso, an amateur astronomer in Argentina, was testing a new camera attached to his 16-inch diameter telescope by taking a series of images of the spiral galaxy NGC 613 when he notice that a faint object had appeared in the outskirts of this galaxy which brightened rapidly over the course of about an hour. It turns out that this was the first ever observations of the long-sought-for "shock break-out" phase that marks the onset of a supernova explosion. Following this discovery and the notification of the astronomical community, extensive observations were made of this supernova, dubbed SN 2016gkg, over the next 2 months that showed it was caused by the explosion of a massive star, and was a Type IIb supernova. The results of this campaign were published by Bersten et al. in Nature in 2018.
2016 Jun 15 At a press conference, it is announced that the Laser Interferometer Gravitational-wave Observatory (LIGO) has detected a second transient gravitational wave source, GW 151226. The waveform of this "Boxing Day" (2015 December 26) event was (like the previous GW 150914 source) was consistent with that produced by the merger of two black holes to produce a single, more massive spinning black hole. The masses of the black holes in this second event were smaller (14 and 8 solar messes) than those of the first event (36 and 29 solar masses) producing a higher frequency signal for about a second (see Abbott et al. (2016, PRL, 116, 241103) for more details on this event).
2016 Mar 26, 16:40 JST Loss of communication with the Hitomi mission, formerly known as Astro-H. Hitomi was to be the next-generation X-ray astronomy satellite of the Japanese space agency (JAXA), and had significant NASA contributions. Unfortunately, in the several weeks of operations before this event, Hitomi had time to make only a few astronomical observations, the most important of which was of the Perseus galaxy cluster. After a month analyzing what occurred to cause the loss of the spacecraft sigmal, JAXA concluded that a series of failures in the attitude control system and recovery procedures had caused the satellite to break up, and that Hitomi was a total loss.
2016 Mar 3 A new contender for the most distant galaxy ever seen in the Universe is announced by Oesch et al. (2016, ApJ, in press). GN-z11 was identified initially as a distant galaxy candidate using CANDELS/GOODS-N imaging data, and was then observed with the HST WFC3/IR slitless grism. It has a spectroscopically confirmed redshift of 11.1, implying that this galaxy formed just 400 million years after the Big Bang. Note that there is a galaxy with a larger, albeit photometrically determined redshift of 11.9 (UDFj-39546284: see the item dated 2012 Dec 12), but this has not been spectroscopically confirmed.
2016 Feb 17, 03:45 am EST Successful launch of the Astro-H mission, now renamed Hitomi, the Japanese word for eye or more specifically the pupil of the eye. Hitomi was a next-generation X-ray astronomy satellite of the Japanese space agency (JAXA), with significant NASA contributions. It was dedicated to the exploration of non-thermal phenomena in the Universe through its hard X-ray imaging, high-resolution spectroscopy, and broad-band coverage. The objectives were the non-thermal X-ray components in cluster of galaxies and SNR, hidden AGN and their contribution to the cosmic X-ray background. Such non-thermal energy comprises a considerable fraction of the total energy in the Universe. NASA provided a high spectral resolution Soft X-ray Spectrometer (SXS) for Hitomi, which consists of an X-Ray Telescope (XRT) and an X-Ray Calorimeter Spectrometer (XCS). The SXS was to probe matter in extreme environments, investigate the nature of dark matter on large scales in the universe, and explore how galaxies and clusters of galaxies form and evolve. The other instruments on Hitomi were provided by the Japanese part of the collaboration, and consist of a focusing Hard X-ray Imager (HXI), a Soft X-ray Imager (SXI) and a Soft Gamma-ray Detector (SGD).
2016 Feb 11 At a National Science Foundation press conference, it is announced that a short burst of gravitational waves was detected on Sep 14, 2015. The discovery of this event (dubbed "GW 150914" after the date of its detection) occurred 100 years after the publication of Einstein's General Theory of Relativity in which their existence was predicted. These ripples in the fabric of space-time arrived at Earth from a cataclysmic event in the distant (redshift ~ 0.1) universe, namely the merger of two black holes to produce a single, more massive spinning black hole, and were detected by the Laser Interferometer Gravitational-wave Observatory (LIGO). This finding opens an unprecedented new window to the cosmos.
2015 Dec 17 Successful launch of the Chinese Academy of Sciences Dark Matter Particle Explorer (DAMPE) satellite, now renamed "Wukong", on a Long March 2-D rocket from the Jiuquan Satellite Launch Center into a 500-km altitude sun-synchronous orbit. This mission will detect high-energy 5 GeV - 10 TeV) gamma rays and electrons with much higher energy resolution and energy reach than achievable with existing space experiments, as well as cosmic rays with energies in the range from 100 GeV to 100 TeV. This will enable DAMPE to search for dark matter in the universe and also study cosmic ray acceleration and propagation.
2015 Dec 3, 05:49 GMT Successful launch of the European Space Agency's LISA Pathfinder mission, formerly known as SMART-2 (Small Missions for Advanced Research in Technology: Second Mission). LISA Pathfinder is a technology demonstration mission which consists of a satellite containing two test masses 35 centimetres apart in a nearly perfect gravitational free-fall. LISA Pathfinder will pave the way for proposed major ESA and/or NASA seience missions in the future such as eLISA/NGO (evolved Laser Interferometer Space Antenna/New Gravitational-wave Observatory), and the various SGO (Space-based Gravitational-wave Observatory) concepts presented at NASA's Physics of the Cosmos Workshop on this subject held in December 2011. These follow--on missions aim to detect gravitational waves generated by very massive objects such as black holes. Detecting gravitational waves will tell us more about the way space and time are interconnected. LISA Pathfinder consists of placing two test-masses in a nearly perfect gravitational free-fall, and of controlling and measuring their motion with unprecedented accuracy. (LISA Pathfinder will check, among other things, sensors that can tell whether a 100 kilogram spacecraft has moved from its position by just 10 millionths of a millimeter). This is achieved through state-of-the-art technology comprising inertial sensors, a laser metrology system, a drag-free control system and an ultra-precise micro-propulsion system. All these technologies are essential not only for eLISA/NGO or SGO; they also lie at the heart of any future space-based test of Einstein's General Relativity.
2015 Sep 28, 04:30 GMT Successful launch of ASTROSAT, India's first multiwavelength astronomy satellite, on the Indian PSLV from the Sriharikota Launch Centre. Most astronomical objects in the known Universe emit radiation spanning the complete electromagnetic spectrum stretching from long wavelength radio emission to extremely short wavelength gamma rays. Hence for a detailed understanding of the physical processes that give rise to frequency-dependent, time-variable phenomena, it is essential to carrry out nearly simultaneous multi-frequency observations. Important areas requiring broad band coverage include studies of astrophysical objects ranging from the nearby solar system objects to distant stars, to objects at cosmological distances; timing studies of variables ranging from pulsations of the hot white dwarfs to active galactic nuclei (AGN) with time scales ranging from milliseconds to few hours to days. ASTROSAT is a multiwavelength astronomy mission with 5 instruments onboard to cover the UV(1000-3000 A), soft and hard x-ray regimes (0.3-8 keV; 2-100 keV). Science objectives of ASTROSAT include:
* Multiwavelength studies of cosmic sources,
* Monitoring the X-ray sky for new transients,
* All-sky survey in the hard X-ray and UV bands,
* Broadband spectroscopic studies of X-ray binaries, AGN, SNRs, clusters of galaxies and stellar coronae,
* Studies of periodic and non-periodic variability of X-ray sources, and
* Monitoring intensity of known sources and detecting outbursts and luminosity variations.
2015 Jun 15, 02:30 EDT Start of a major outburst of the the X-ray binary system V404 Cygni. The brightening in X-rays was discovered by Swift and MAXI, and it was soon realized that the black hole in this system was having a major outburst, a so-called X-ray nova. Many hard X-ray flares were detected in the next several weeks, with the brightest reaching a level of order 50 times brighter than the Crab (6.8 e-07 erg cm-2 s-1) in the 15-200 keV energy band, equivalent to the Eddington luminosity for a 12 solar mass black hole (1.6 e39 erg s-1) at its distance of 2.4 kpc, according to Segreto et al. (2015, ATel 7755).
2015 The level of carbon dioxide (CO2) in the Earth's atmosphere reaches 400 parts per million (ppm), compared to a level of 280 ppm for most of the previous 10 millennia: this is the highest level of CO2 in the last 650,000 years. This 43% increase occurred over the last 250 years and is believed to be anthropogenic, primarily due to the burning of fossil fuels and deforestation. The NASA Global Climate Change website has much more information on this subject.
2015 Jan 15, 09:09 UT The hard X-ray Burst Alert Telescope (BAT) on the Swift satellite detected a very bright, hard X-ray flare from SZ Psc, a 3.97-day period RS CVn binary system located 97 pc from the Sun. Swift soft X-ray (XRT) and optical (UVOT) pointed observations began 6.3 minutes after the BAT trigger and Swift continued to monitor this source for ~ 1 day. Preliminary analysis confirms that this flare had likely the second highest (250 million K) peak temperature for a stellar flare ever observed, while its peak X-ray-luminosity of 5 x 1033 erg/s may be the most powerful X-ray flare ever detected from any active late-type star: see Drake et al. 2015, ATel, No. 6940 for more details.


Mid-2014 Epoch of closest approach (17 light hours = 18 billion km) of the small gas cloud/emission-line object dubbed G2 to Sgr A*, the central super-massive black hole of our Galaxy, according to Gillessen et al. (2012, Nature, 481, 51) and Phifer et al. (2013, arXiv: 1304.5280). The tidal forces of the 4 million solar mass black hole were expected to shred this cloud into fragments as it approached, with some fraction of the gas 'feeding the monster', i.e., falling into its gravitational well and likely causing a significant brightening of Sgr A*'s current X-ray luminosity from its present value of ~ 3 x 1033 erg/s (~ 1 Lsun). If there is a central stellar object inside G2 as Phifer et al. argue, this star would likely survive this encounter as it would have survived previous periapses ('perigalacticons'?), and will have the next such close encounter in a few centuries time. As of the end of 2014, no X-ray brightening had been observed from Sgr A*, giving support to the hypothesis that it is a gas-enshrouded star rather than a gas cloud.

If Sgr A* were ever to get a sufficient supply of accreting matter and radiate at the maximum possible level, the Eddington Limit, which is Lx ~ 5 x 1044 erg s-1 (~ 1011 Lsun) for such a massive object, its luminosity would exceed the bolometric luminosity of the entire Milky Way galaxy (~5 x 1043 erg s-1) by a factor of 10! As seen from the Earth, the observed X-ray flux of Sgr A* in this state of 5.8 x 10-2 erg/s/cm2 would far exceed the flux of every other object in the sky in X-rays as seen from the Earth, with the sole exception of the Sun (fx ~ 0.1 - 10 erg/s/cm2)!

2014 Apr 23, 21:07 UT The hard X-ray Burst Alert Telescope on the Swift satellite detects an unusually intense `superflare' from DG CVn, a wide M dwarf star binary system 18 pc from the Sun. Swift soft X-ray (XRT) and optical (UVOT) pointed observations began 2 minutes later and Swift continued to monitor this source for 10 days. Preliminary analysis confirms that this was likely the hottest (300 million K), longest (~ 2 weeks) and most X-ray-luminous (2 x 1032 erg/s) stellar flare ever detected from an M dwarf star in the solar neighborhood. At its peak and for several minutes, this flare was brighter than the binary system's normal bolometric luminosity (see Drake et al. (2014, ATel, No. 6121) and Osten et al. (2015, in preparation) for more details).
2013 Oct 23 Decommissioning of ESA's Planck spacecraft. After spending 4.5 years at the Earth-Sun L2 Lagrange point making detailed observations (five all-sky surveys) of the cosmic microwave background (CMB), Planck was put into a heliocentric "parking" orbit so that at least for several hundred years it will stay clear of the Earth-Moon system. Planck continuously measured the intensity of the sky over a range of frequencies from 30 to 857 GHz (wavelengths of 1 cm to 350 micron) with spatial resolutions ranging from about 33 to 5 arcminutes, respectively, in order to precisely measure the characteristics of the cosmic microwave background (CMB) and thereby accurately determine the fundamental parameters of the Universe such as its age and precise constituents: to wit, 13.82 billion years, and 4.9% normal 'baryonic" matter, 26.8% "dark" matter, and 68.3% "dark energy", respectively.
2013 Jun 28, 15:09 EDT Decommissioning of NASA's GALEX (Galaxy Evolution Explorer) satellite, a Small Explorer mission that observed the Universe in ultraviolet wavelengths for over 10 years (several times its original mission lifetime), and made many major discoveries, e.g., the glowing 13-light years long trail, left by the star Mira as is speeds through the interstellar medium, the presence of ongoing star formation in a galaxy previously thought to be "essentially dead", etc.
2013 Jun 17 Decommissioning of ESA's Herschel spacecraft. After spending almost 4 years at the Earth-Sun L2 Lagrange point making detailed observations in the far-infrared and sub-millimeter spectral range (55-671 microns), Herschel was put into a heliocentric "parking" orbit so that at least for several hundred years it will stay clear of the Earth-Moon system. Herschel made over 35,000 scientific observations, amassing more than 25,000 hours' worth of science data from about 600 observing programmes. A further 2000 hours of calibration observations were made. According to Goran Pilbratt, ESA's Herschel Project Scientist, "Herschel has offered us a new view of the hitherto hidden Universe, pointing us to a previously unseen process of star birth and galaxy formation, and allowing us to trace water through the Universe from molecular clouds to newborn stars and their planet-forming discs and belts of comets".
2013 Apr 27, 07:47:06 UT A gamma-ray burst (GRB 130427A) was detected by NASA's Fermi Gamma-Ray Space Telescope Gamma-Ray Burst Monitor (GBM) which triggered a spacecraft repoint to bring the location into the field of view of Fermi's Large Area Telescope (LAT). GRB 130427A had the largest observed fluence, the highest-energy detected photon (95 GeV), the longest γ-ray duration (20 hours) and one of the largest isotropic energy releases ever observed from any GRB. This observation (discussed by Ackermann et al. 2013, Science, in press), particularly the detection of a 95 GeV photon in the early afterglow of the GRB 244 seconds after the prompt emission, challenges the standard model of the emission in this subsequent phase being produced by shock Fermi acceleration.
2013 Feb 15 A small (17-20 m diameter, 11,000 tons mass) asteroid explodes above Chelyabinsk, Russia releasing an energy equivalent to ~100 kilotons of TNT in its fireball, damaging thousands of buildings and injuring about 1500 people, mostly due to broken glass from windows. This is the largest object known to have impacted the Earth since since the 1908 Tunguska event.
2012 Dec 12 NASA announces that Hubble has "seen further back in time than ever before and has uncovered a previously unseen population of seven primitive galaxies that formed more than 13 billion years ago, when the universe was less than 3% of its present age". One of the objects found by Ellis et al. (2013, ApJ, 763, L7) in their 2012 re-observation of the Hubble Ultra Deep Field, UDFj-39546284, "may be a [new] distance record breaker, observed 380 million years after the birth of our universe in the big bang, corresponding to a redshift z of 11.9". The previous highest-redshift object, MACS0647-JD (z ~ 11), only 'reigned' for about 1 month (see item dated 2012 Nov 15) before being deposed!
2012 Nov 15 NASA announces that Hubble and Spitzer observations of a gravitational lens (Postman et al. 2012, ApJ, in press) have discovered the most distant/oldest galaxy yet, MACS0647-JD, with an estimated redshift of 11, equivalent to an age of 13.3 billion years, only 420 million years after the big bang. The new distance champion is the second remote galaxy uncovered in the CLASH survey, a multi-wavelength census of 25 hefty galaxy clusters with Hubble's ACS and WFC3. MACS0647-JD is so small it may be in the first steps of forming a larger galaxy. An analysis shows the galaxy is less than 200 parsecs across, much smaller than the current size of 50,000 pc of our own Milky Way Galaxy.
2012 Jun 13, 16:00:37 UT Successful launch on a Pegasus rocket of NASA's Nuclear Spectroscopic Telescope Array (NuSTAR) mission. NuSTAR is a pathfinder mission that will open the high-energy X-ray sky for sensitive study for the first time. X-ray telescopes like Chandra and XMM-Newton have peered deep into the X-ray universe at low X-ray energy (X-ray energies less than 10 keV). By focusing X-rays at higher energies (up to 80 keV), NuSTAR will answer fundamental questions about the Universe, including:
How are black holes distributed through the cosmos?
How were the elements that compose our bodies and the Earth forged in the explosions of massive stars?
What powers the most extreme active galaxies? NuSTAR's archive of data is available at the HEASARC.
2012 June 5 Death of Ray Bradbury (1920 - 2012), noted fantasy and science fiction writer, who wrote influential books such as 'The Martian Chronicles' and 'Fahrenheit 451' and stories such as 'The Sound of Thunder'. Despite his interest in future technology, Bradbury was skeptical and worried about its effects on humanity: "We've got too many Internets. We have to get rid of those machines. We have too many machines now" he is quoted as saying.
2012 Jan 3 End of scientific operations of NASA's Rossi X-ray Timing Explorer (RXTE) spacecraft after 16 years of highly successful operations. In celebration of its many contributions to astronomy, there was a special RXTE session at the January 2012 AAS Meeting in Austin, Texas and a symposium at Goddard Space Flight Center in Greenbelt, Maryland on March 29 and 30, 2012. RXTE's legacy archive of data is available at the HEASARC.
2011 Oct 23, ~01:50 UTC Re-entry and destruction in the Earth's atmosphere of ROSAT (Roentgen Satellite), a German Aerospace Center (DLR for Deutsches Zentrum fuer Luft- und Raumfahrt) satellite with X-ray and extreme-ultraviolet detectors, likely somewhere in a region with a large uncertainty ranging over the Indian Ocean, the Andaman Sea, Myanmar, Laos and China according to Jonathan McDowell. ROSAT was the workhorse high-energy astrophysics mission of the 1990s, conducting an all-sky survey in the soft X-ray band (0.1 - 2.5 keV) in 1990 and then many pointed observations through late 1998. Despite its fiery demise, ROSAT's legacy archive of data is available at the HEASARC.
2011 Mar 18 Insertion into orbit around Mercury of NASA's MESSENGER (Mercury Surface, Space Environment, Geochemistry, and Ranging) spacecraft. In order to become the first spacecraft ever to orbit Mercury, MESSENGER followed a tortuous path through the inner solar system, including one flyby of Earth, two flybys of Venus, and three flybys of Mercury itself. MESSENGER's science goals during the year-long orbital phase of its mission are to provide the first images of the entire planet and to collect detailed information on the composition and structure of Mercury's crust, its geologic history, the nature of its thin atmosphere and active magnetosphere, and the makeup of its core and polar materials.
2011 Feb 17, 12 noon PST Turn-off of the Wide-field Infrared Survey Explorer (WISE) spacecraft transmitter signalling the end of scientific operations, after completion of both its primary cryogenic mission, an infrared sky survey, and of its post-cryogenic "NEOWISE" mission. The latter was designed to complete WISE's survey of the solar system, including near-earth objects (NEOs), and its 2nd all-sky survey, albeit only in its 2 shorter-wavelength IR bands.
2011 Jan 27 The discovery of the (as of this date) likely most distant/oldest object yet known, the proto-galaxy UDFj-39546284, is announced in an article by Bouwens et al. (2011 Nature, 469, 504). This galaxy was photometrically identified as a likely high-redshift (z ~ 10.3) object in the Hubble Ultra-Deep Field: this redshift corresponds to an age within only 480 Myrs of the Big Bang.
2010 Dec 25, 1:38pm EST The Swift Burst Alert Telescope detects the start of a gamma-ray burst (GRB 101225A), the emission from which lasted 28 minutes, unusually long for GRBs. This very long duration has led to two very different competing explanations for what produced it: either a novel type of sypernova located billions of light years away, or an unusual collision of a large comet-like object with a neutron star within our own Galaxy.
2010 Nov 30 First science flight of the Stratospheric Observatory for Infrared Astronomy (SOFIA), a joint project of NASA and DLR (the German Aerospace Center), demonstrating the aircraft's potential to make discoveries about the infra-red universe. The Boeing 747SP-based telescope made a 10-hour flight at altitudes up to 45,000 feet where the sky is much more transparent to IR radiation than at lower altitudes, and made scientific observations using the highly sensitive Faint Object Infra-Red Camera for the SOFIA Telescope (FORCAST) at wavelengths of 5.4, 24 and 37 microns. This flight "mark[ed] SOFIA's transition from flying testbed to flying observatory" according to Bob Meyer, NASA's SOFIA program manager.
2010 Oct 21 The discovery of the (as of this date) most distant galaxy yet, UDFy-38135539, is announced in an aticle by Lehnert et al. (2010 Nature, 467, 924). This galaxy was photometrically identified as a likely high-redshift object in the Hubble Ultra-Deep Field, and the authors' 14.8 hrs long spectroscopic follow-up with the ESO Very Large Telescope detected an emission line at 1.1616 microns which, if redshifted Lyman-α, implies a redshift of 8.555, corresponding to an age of within 600 Myrs of the Big Bang. This record-breaker was superceded on 2011 January 27 (q.v.) by the announcement of the discovery of the (proto-)galaxy UDFj-39546284 with a redshift of ~10
2010 Aug 19 The end of operations of NASA's Wilkinson Microwave Anisotropy Probe (WMAP), a mission designed to determine the geometry, content, and evolution of the universe via a 13 arcminute FWHM resolution full-sky map of the temperature anisotropy of the cosmic microwave background radiation. It succeeded brilliantly in these goals: in the words of the astronomer John Bahcall, WMAP turned "cosmology from speculation to precision science" (see, for example, this table of cosmological parameters). WMAP's legacy archive of data is available at the Legacy Archive for Microwave Background Data Analysis (LAMBDA, part of the HEASARC) website.
2010 Jun 21, 03:03:32 UT The Swift satellite detected a 200-second long gamma-ray burst (GRB 100621A), and rapidly slewed to point its narrow-field optical/UV and X-ray detectors at it. No optical afterglow was seen, although a near-IR afterglow was detected in ground-based observations by Greiner et al (2010, GCN Circular 10874), but intense X-ray emission was detected, with a peak level 14 times brighter than the X-ray flux of Sco X-1. This X-ray flux (~3 x 10-6 erg s-1 cm-2) is the brightest ever detected for a GRB.
2010 May 26 First-light flight of the Stratospheric Observatory for Infrared Astronomy (SOFIA), a joint project of NASA and DLR (the German Aerospace Center), ushering in a new era of infra-red observational capabilities. The Boeing 747SP-based telescope made a 6-hour flight at altitudes up to 35,000 feet where the sky is much more transparent to IR radiation than at lower altitudes, and made scientific observations of Jupiter and M82 using the highly sensitive Faint Object Infra-Red Camera for the SOFIA Telescope (FORCAST) at wavelengths of 5.4, 24 and 37 microns. The image stability and pointing precision of these observations met or exceeded the pre-flight expectations.
2010 Feb 11 Launch of NASA's Solar Dynamics Observatory (SDO). SDO is designed to help us understand the Sun's influence on the Earth and the near-Earth space by studying the solar atmosphere at exquisitely fine scales in both space and time and at many wavelengths including the visible, ultraviolet, extreme-ultraviolet and X-ray regions.
SDO contains a suite of instruments that will provide observations leading to a more complete understanding of the solar dynamics that drive variability in the Earth's environment. This set of instruments will:
1. Measure the extreme ultraviolet spectral irradiance of the Sun at a rapid cadence
2. Measure the Doppler shifts due to oscillation velocities over the entire visible disk
3. Make high-resolution measurements of the longitudinal and vector magnetic field over the entire visible disk
4. Make images of the chromosphere and inner corona at several temperatures at a rapid cadence
5. Make those measurements over a significant portion of a solar cycle to capture the solar variations that may exist in different time periods of a solar cycle
2010 Jan 26 The Death of Geoffrey Burbidge, a leading astrophysicist of the twentieth century, and co-author of one of the most influential astronomy papers of all time, yclept B2FH, published in 1957, which presented a detailed theory and observational support for stellar "nucleosynthesis". This theory stated that all but the lightest elements in the Universe were created by nuclear reactions inside stars and supernovae, i.e., 'we are stardust, billion year old carbon' (Joni Mitchell 1969, private communication).


2009 Dec 14 Launch of NASA's Wide-field Infrared Survey Explorer (WISE) spacecraft on a Delta II rocket from Vandenberg Air Force Base. WISE will provide an all-sky survey from 3 to 25 microns with 500,000 times the sensitivity of the Cosmic Background Explorer (COBE) Diffuse Infrared Background Experiment (DIRBE) and hundreds of times that of the Infrared Astronomical Satellite (IRAS). The survey will help search for the origins of planets, stars, and galaxies and create an infrared atlas whose legacy will endure for decades. WISE will:
* Find the most luminous galaxies in the Universe
* Find the closest stars to the Sun
* Detect most Main Belt asteroids larger than 3 km
* Enable a wide variety of studies ranging from the evolution of planetary debris discs to the history of star formation in normal galaxies
* Provide an important source catalog for the upcoming James Webb Space Telescope (JWST).
2009 400th anniversary of Galileo's first telescopic observations. This will be celebrated as the International Year of Astronomy 2009 (IYA2009), "a global celebration of astronomy and its contributions to society and culture", to be coordinated by the International Astronomical Union (IAU).
2009 Jul 15 Launch of space shuttle Endeavour on the STS-127 mission, which carried (inter alia) the JAXA Monitor of All-Sky X-ray Image (MAXI) experiment for installation on the International Space Station (ISS). MAXI is an all-sky X-ray scanner, consists of X-ray slit cameras with high sensitivity, which will continuously monitor X-ray-emitting astronomical objects over a broad energy band (0.5 to 30 keV), i.e., it is an X-ray all-sky monitor.
2009 May 14 Launch of the ESA Herschel mission on an Ariane 5 rocket, which also carried the Planck observatory, from Kourou, French Guiana. Following a cruise to the Earth-Sun L2 Lagrange point, thermal stablization of the cryogenically cooled telescope and a performance verification phase, Herschel began making science observations on 11 September 2009. Herschel offered unprecedented observational capabilities in the far-infrared and sub-millimeter spectral range (55-671 microns [um]): it carried a 3.5-m diameter passively cooled Cassegrain telescope, which was the largest of its kind and utilized a novel silicon carbide technology.
2009 May 14 Launch of the ESA Planck mission on an Ariane 5 rocket, which also carried the Herschel observatory, from Kourou, French Guiana. Following a cruise to the Earth-Sun L2 Lagrange point, cooling and in-orbit checkout, Planck initiated the First Light Survey on 13 August 2009. From then on, Planck continuously measured the intensity of the sky over a range of frequencies from 30 to 857 GHz (wavelengths of 1 cm to 350 micron) with spatial resolutions ranging from about 33 to 5 arcminutes, respectively, in order to precisely measure the characteristics of the cosmic microwave background (CMB).
2009 May 12 Launch of the Space Shuttle Atlantis on the STS-125 mission to repair and expand the capabilities of the Hubble Space Telescope (HST). This was the fifth and final servicing mission to HST and should enable it to continue operations through 2013, and potentially even longer, funding permitting.
2009 Apr 29 The Swift satellite detects a 6-second long gamma-ray burst (GRB 090429B), which optical and infrared follow-up observations performed using the Gemini North Telescope, the Very Large Telescope and the GRB Optical and Near-Infrared detector suggest is the most distant GRB ever detected, with a photometric redshift of 9.4 which translates to a distance of 13.14 billion light years from Earth. This discovery, announced by Cucchiara et al. (2011, ApJ, accepted) on 2011 May 25, makes this one of the most distant individual objects of any type that has ever been observed, even more distant than the redshift 8.555 galaxy UDFy-38135539 announced on 2009 Oct 21, but not quite as distant as the proto-galaxy UDFj-39546284 (z ~ 10.3) announced on 2011 Jan 27.
2009 Apr 23 The Swift satellite detects a 10-second long gamma-ray burst (GRB 090423), which infrared follow-up observations performed using the UKIRT and the Gemini North Telescope confirm is the most distant GRB ever detected to this date, with a redshift of 8.2 which translates to a distance of 13.035 billion light years from Earth. This was also the most distant individual object of any type that had ever been observed, until the announcement on 2009 Oct 21 of the redshift 8.555 galaxy UDFy-38135539 and the announcement on 2011 May 25 of the redshift 9.4 GRB 090429B.
2008 Oct 1 50th anniversary of the start of operations of NASA, the National Aeronautics and Space Administration, in 5 facilities inherited from the National Advisory Committee on Aeronautics (NACA) agency which it subsumed, together with space projects and appropriations from other space programs. These gave NASA 8,240 staff (8,000 from the NACA) and a budget of approximately $340 million.
2008 Jul 29 50th anniversary of the signing into law of the act establishing NASA, the National Aeronautics and Space Administration, the civilian space agency of the United States of America, by President Dwight D. Eisenhower.
2008 Jun 11, 12:05 pm EDT Successful launch on a Delta II Heavy rocket of the Fermi Gamma-Ray Space Telescope, formerly known as the Gamma-Ray Large Area Space Telescope (GLAST), a NASA/DOE mission with international partners. Fermi is a next-generation high-energy gamma-ray observatory designed for making observations of celestial gamma-ray sources in the broad energy band extending from 10 MeV to more than 100 GeV. It follows in the footsteps of the CGRO-EGRET experiment, which was operational between 1991-1999. The key scientific objectives of the Fermi mission are:
1. To understand the mechanisms of particle acceleration in AGNs, pulsars, and SNRs.
2. To resolve the gamma-ray sky: unidentified sources and diffuse emission.
3. To determine the high-energy behavior of gamma-ray bursts and transients.
4. To probe dark matter and the early Universe.
Fermi's large archive of data is available at the HEASARC.
2008 May 25 Successful soft-landing on the northern plains of Mars of NASA's Phoenix Mars Mission. Once it was fully activated, Phoenix dug into the soil, discovering subsurface water-ice, and performed chemical analyses which were designed to help scientists understand the past and present habitability of this unique environment for (hypothetical) Martian microbes.
2008 Apr 25, 05:12-08:00 UT The Swift satellite detects an unusually intense X-ray `superflare' from the single nearby M dwarf star EV Lacertae. Analysis confirms that this is the brightest stellar flare ever detected in the X-ray band, e.g., the peak X-ray flux is 3 x 10-8 erg s-1 cm-2 in the 0.3-10.0 keV band. This flare was bright enough in the hard X-ray range that it was also detected in the 20-70 keV energy band by the Konus S2 gamma-ray burst detector on NASA's Wind satellite. At its peak, this flare was brighter than the star's entire bolometric luminosity (see Osten et al. 2008, ATel, No. 1499 for more details).
2008 Mar 19 NASA's Swift satellite observes the brightest gamma-ray burst optical afterglow yet detected. The afterglow of GRB 080319B was bright enough to have been seen with the naked eye, reaching a maximum brightness between 5th and 6th magnitude. Spectra indicate that this object has a cosmological redshift of 0.937, meaning that it is 7.5 billion light years away (in light travel time distance), and that the explosion actually happened 7.5 billion years ago, i.e, 3 billion years before the Sun and solar system formed: see Bloom et al. (2009, ApJ, 691, 723) and Wozniak et al. (2009, ApJ, 691, 495) for more details on this "most luminous optical object ever recorded by humankind".
2008 Mar 19 Death of Arthur C. Clarke (1917 - 2008), noted science fiction writer and futurologist, who inspired many people all over the world with his prescient and elegant visions of humanity's and the universe's past, present and future, and the roles and limitations of technology:
"Open the pod bay doors, HAL", and not forgetting:
"overhead, without any fuss, the stars were going out".
2007 Aug 30 NASA's Voyager 2 spacecraft, launched in 1977, crosses the solar wind termination shock (multiple times) and enters the heliosheath region, the transition region between the region dominated by the solar wind (the "heliosphere") and the true interstellar medium.
2007 Aug 4 Successful launch on a Delta II rocket of NASA's Phoenix Mars Mission, a spacecraft that will soft land on the northern plains of Mars on May 25th 2008. Once safely landed, Phoenix will literally dig into the soil and subsurface water-ice and perform chemical analyses designed to help scientists better understand the past and present habitability of this unique environment for hypothetical Martian microbes.
2007 Apr 26 First low-altitude (up to 10,500 feet) test flight of the Stratospheric Observatory for Infrared Astronomy (SOFIA), a joint project of NASA and DLR (the German Aerospace Center). Normal operations for this Boeing 747SP-based telescope will be conducted at altitudes above 40,000 feet where the sky is much more transparent to IR radiation than at lower altitudes. The first flight on which general astronomical observations will be made is currently expected to be in 2010.
2007 Apr 23 Successful launch on an Indian Space Research Organization (ISRO) PSLV rocket of the Agile (Astro-rivelatore Gamma a Immagini LEggero, or Light Astro Gamma Imaging Detector) payload. AGILE is an Italian Space Agency gamma-ray mission conceived as a bridge between the EGRET gamma-ray detector on the Compton Gamma-Ray Observatory (CGRO) and the GLAST mission. The AGILE telescope (30 MeV - 50 GeV) will measure the electron and positron resulting from the gamma-ray pair conversion process, together with a calorimeter that will determine the energy. An anti-coincidence detector will separate the gamma rays from the background of cosmic ray charged particles found in space. Smaller than EGRET, improved technology gives AGILE comparable on-axis sensitivity, a much wider field of view (about 3 sr, or one-fourth of the sky), better angular resolution (5 - 20 arcminutes for strong sources) and a much smaller deadtime (less than 1 millisecond). This combination of features will allow AGILE to expand on the EGRET discoveries significantly and set the scientific groundwork for the much larger NASA GLAST mission. AGILE should be ideal for detecting AGN flaring activity, gamma-ray bursts, pulsars, new transients, solar flares, and cosmic-ray interactions in the Galaxy.
2007 Feb 28, 05:44 UT Closest approach to Jupiter of NASA's New Horizons spacecraft. New Horizons received a velocity boost due to Jupiter's gravity to help speed it on its way to Pluto, which it is scheduled to encounter in July 2015.
2006 Aug 13, 21:13 UT NASA's Voyager 1 spacecraft, launched in 1977, becomes the most distant human artifact in space, reaching a distance of 100 Astronomical units (15 billion km) from the Sun, on its way to and beyond the edge of the solar system or heliopause.
2006 Jan 19, 19:00 UT The successful launch of NASA's New Horizons spacecraft on its 9.5 year flight to Pluto and its moon Charon via Jupiter (from which it will get a velocity boost using the gravity assist from a close approach). New Horizons is the first spacecraft dedicated to the exploration of the Pluto-Charon system, and it may go on to explore even more distant Kuiper Belt Objects after its Pluto fly-by in 2015.
2005 Dec 16 The Swift satellite detects an unusually intense X-ray `superflare' from the binary system II Pegasi. Analysis confirms that this is one of the brightest stellar flares ever detected in the X-ray band, e.g., 100,000 times more X-ray luminous than the most intense solar flare yet seen, and the detection of X-rays up to an energy of 200 keV strongly favors a non-thermal model for the hard X-rays (see Osten et al. 2007, ApJ, 654, 1052).
2005 Sep 29 The end of the data collection phase for the Gravity Probe-B (GP-B) spacecraft, when the helium in its dewar was finally exhausted. This experiment had four incredibly precise, supercooled gyroscopes which tested two predictions of Einstein's theory of general relativity, namely the existence and the magnitude of the gravitomagnetic (`frame-dragging' of space-time by the rotating earth in this case) and the geodetic (the space-time curvature caused by the gravitational field of the earth) effects that are predicted by this theory. This mission is now in the data analysis phase, currently expected to continue until September 2008, although preliminary reports are that GP-B has already confirmed the presence of the geodetic effect (170 times larger than the frame-dragging effect) to a precision of better than 1%.
2005 Sep 4 The Swift satellite detects an unusually long (200 seconds) gamma-ray burst (GRB 050904), which optical follow-up observations confirm is one of the most distant GRBs ever detected, with a redshift of 6.29 which translates to a distance of 12.7 billion light years. Only two other objects, a quasar with a redshift of 6.4 and a GRB in 2008 (GRB 080913) with a redshift of 6.7, had been discovered at greater redshift/distance than this GRB by this date (but the new record holder is the 2009 April 23 GRB, q.v.).
2005 Jul 9 Successful launch of the Suzaku (formerly called ASTRO-E2) X-Ray Observatory, a replacement of the ASTRO-E mission which suffered a launch failure on February 10 2000. Suzaku is Japan's fifth X-ray astronomy mission, and was developed by Japan Aerospace Exploration Agency's (JAXA) Institute of Space and Astronautical Science (ISAS) in collaboration with U.S. (NASA/GSFC, MIT) and other Japanese institutions. Suzaku covers the high-energy range from 0.4 - 700 keV with three instruments, an X-ray micro-calorimeter (X-ray Spectrometer; XRS, unfortunately inoperational after 1 month), four X-ray CCDs (X-ray Imaging Spectrometer; XIS), and the Hard X-ray Detector (HXD). Suzaku uses the Universe as a laboratory for unraveling complex, high-energy processes and the behavior of matter under extreme conditions. Scientific issues that will be addressed during its mission include the fate of matter as it spirals into black holes, the nature of supermassive black holes found at the center of quasars, the 100 million degree gas that is flowing into giant clusters of galaxies, and the nature of supernova explosions that create the heavier elements, which ultimately form planets. Suzaku's legacy archive of data is available at the HEASARC.
2005 Jul 4, 1:52 am EDT Impact of NASA's Deep Impact impactor spacecraft with Comet Tempel 1 at a relative velocity of 10 km/s (23,000 mph), generating an intense flash of light, and starting a prolonged outburst of comet material. This event and its aftermath were observed by the nearby Deep Impact mothership, as well as a host of other ground- and space-based telescopes and observatories, including the Chandra, RXTE, and XMM-Newton X-ray observatories, and the Swift multi-wavelength suite of detectors. Analysis of all these datasets should yield unique and valuable information about the space environment, interior composition and structure of this comet. Early results indicate that Tempel 1 was detected as an X-ray source by XMM-Newton and Chandra. The observed X-rays are likely the result of charge exchange between cool neutral material in the comet's coma and highly charged solar wind ions.
2005 This year was designated the World Year of Physics: Einstein in the 21st Century by the International Union of Pure and Applied Physics as a celebration of the centenary of Albert Einstein's `miraculous year' of 1905 in which he published 3 of his most influential papers.
2005 May 9, 5:03:23 UT First accurate localization of a short gamma-ray burst, GRB 050509b, by instruments on NASA's Swift Gamma-Ray Burst Mission. This GRB lasted only 40 milliseconds, and was followed by a 5-minutes X-ray afterglow that was studied by Swift's X-Ray telescope. No associated optical afterglow was detected, either by Swift's Ultraviolet and Optical Telescope or by ground-based telescopes, but the location of this GRB on the outskirts of a 2.6 billion light years-distant elliptical galaxy suggests that it (and presumably other short GRBs) is the birth `scream' of a black hole as it forms from the merger of two neutron stars (or of two pre-existing black holes, or of a neutron star with a pre-existing black hole) in a close binary system. See Gehrels et al. (2005, astro-ph/0505630) for more details.

Index by Year Range

BCE (BC) 1 - 999 CE (AD) 1000 - 1499 CE (AD) 1500 - 1599 CE (AD) 1600 - 1699 CE (AD)
1700 - 1799 CE (AD) 1800 - 1899 CE (AD) 1900 - 1959 CE (AD) 1960 - 1964 CE (AD) 1965 - 1969 CE (AD)
1970 - 1974 CE (AD) 1975 - 1979 CE (AD) 1980 - 1984 CE (AD) 1985 - 1989 CE (AD) 1990 - 1994 CE (AD)
1995 - 1999 CE (AD) 2000 - 2004 CE (AD) 2005 - 2009 CE (AD) 2010 - 2014 CE (AD) 2015 - 2020 CE (AD)
2020 - 2024 CE (AD) 2025 - 2029 CE (AD) 2030 - 2034 CE (AD) 2035 - 2039 CE (AD)


We would like to thank the following individuals for their contributions to this page: Jesse S. Allen, and Ian M. George along with JPL's Space Calendar and the Working Group for the History of Astronomy's Astronomiae Historia (History of Astronomy) information pages.

All dates/times are east-coast time for the U.S.A., unless otherwise stated. NET means 'no earlier than'. Please send information concerning dates/deadlines not currently included on this page and/or corrections to:


Web page author: Stephen A. Drake (based on an original by Jesse S. Allen)

Web page maintainer: Antara R. Basu-Zych

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