Institute of Astronomy

Astronomy News

Atmosphere found around Earth-like planet GJ 1132b

7 April 2017 - 9:00am

Astronomers make the first detection of an atmosphere surrounding a "super-Earth" planet.

Earth-sized telescope set to snap first picture of a black hole

6 April 2017 - 9:20am

The Event Horizon Telescope will take images of the black hole at the centre of our galaxy, and could reveal how relativity and quantum mechanics mesh

A massive, quiescent galaxy at a redshift of 3.717

6 April 2017 - 9:18am

A massive, quiescent galaxy at a redshift of 3.717

Nature 544, 7648 (2017). doi:10.1038/nature21680

Authors: Karl Glazebrook, Corentin Schreiber, Ivo Labbé, Themiya Nanayakkara, Glenn G. Kacprzak, Pascal A. Oesch, Casey Papovich, Lee R Spitler, Caroline M. S. Straatman, Kim-Vy H. Tran & Tiantian Yuan

Finding massive galaxies that stopped forming stars in the early Universe presents an observational challenge because their rest-frame ultraviolet emission is negligible and they can only be reliably identified by extremely deep near-infrared surveys. These surveys have revealed the presence of massive, quiescent early-type galaxies appearing as early as redshift z ≈ 2, an epoch three billion years after the Big Bang. Their age and formation processes have now been explained by an improved generation of galaxy-formation models, in which they form rapidly at z ≈ 3–4, consistent with the typical masses and ages derived from their observations. Deeper surveys have reported evidence for populations of massive, quiescent galaxies at even higher redshifts and earlier times, using coarsely sampled photometry. However, these early, massive, quiescent galaxies are not predicted by the latest generation of theoretical models. Here we report the spectroscopic confirmation of one such galaxy at redshift z = 3.717, with a stellar mass of 1.7 × 1011 solar masses. We derive its age to be nearly half the age of the Universe at this redshift and the absorption line spectrum shows no current star formation. These observations demonstrate that the galaxy must have formed the majority of its stars quickly, within the first billion years of cosmic history in a short, extreme starburst. This ancestral starburst appears similar to those being found by submillimetre-wavelength surveys. The early formation of such massive systems implies that our picture of early galaxy assembly requires substantial revision.

NASA’s Cassini Mission Prepares for 'Grand Finale' at Saturn

5 April 2017 - 9:07am
Portal origin URL: NASA’s Cassini Mission Prepares for 'Grand Finale' at SaturnPortal origin nid: 399549Published: Tuesday, April 4, 2017 - 15:09Featured (stick to top of list): noPortal text teaser: NASA's Cassini spacecraft, in orbit around Saturn since 2004, is about to begin the final chapter of its remarkable story. On Wednesday, April 26, the spacecraft will make the first in a series of dives through the 1,500-mile-wide (2,400-kilometer) gap between Saturn and its rings as part of the mission’s grand finale.Portal image: This illustration shows NASA’s Cassini spacecraft above Saturn's northern hemisphere prior to one of its 22 grand finale dives. Science Categories: Solar System

NASA’s Cassini Mission Prepares for 'Grand Finale' at Saturn

5 April 2017 - 9:06am
NASA's Cassini spacecraft, in orbit around Saturn since 2004, is about to begin the final chapter of its remarkable story. On Wednesday, April 26, the spacecraft will make the first in a series of dives through the 1,500-mile-wide (2,400-kilometer) gap between Saturn and its rings as part of the mission’s grand finale.

Rosetta's intimate portrait of a comet: read all about it

5 April 2017 - 9:04am

Rosetta's pioneering mission to explore a comet in unprecedented detail completed operations last year. As the science continues, members of the public, as well as scientists, can freely access hundreds of papers that reveal the comet's secrets. A special issue of Monthly Notices of the Royal Astronomical Society is the latest journal to provide this service.

Oldest dust ever spotted in the universe seen in distant galaxy

4 April 2017 - 9:11am

We’ve spotted dust in a galaxy whose light reaches us from when the universe was only 600 million years old – a game changer for studying the earliest galaxies

NASA orbiter shows Mars lost 90 per cent of its CO2 to space

3 April 2017 - 9:08am

The MAVEN spacecraft has completed the key part of its mission: to track down how much argon Mars’s atmosphere is giving up as a proxy for carbon dioxide loss

Gravitational waves slow the spin of shape-shifting neutron star

3 April 2017 - 9:08am

A tiny bump on a star could change how it rotates and possibly explain why there seems to be a speed limit for spinning neutron stars

Mapping Hydrogen to Locate Water on the Moon

3 April 2017 - 9:07am

Technology Infused: The Lunar polar Hydrogen Mapper (LunaH-Map) mission is a CubeSat that will detect the amount of hydrogen at the moon’s South Pole.

LunaH-Map Spacecraft Design (cutaway views).

Designed to fly around the moon in a polar orbit at low altitude (5-12 km), LunaH-Map will carry two newly designed neutron spectrometers to produce highresolution maps of near-surface hydrogen. Previous moon missions have indicated that there is an abundance of hydrogen near the lunar poles, but the exact locations were not determined.

The presence of hydrogen indicates the presence of water, and LunaHMap will provide important constraints on the location and abundance of ice deposits near the lunar South Pole. The spectrometers on LunaH-Map will measure the energies of neutrons that have interacted with and subsequently leaked back out of the material in the top meter of the lunar surface. To accomplish this task, the mission will employ new technology—an elpasolite scintillation detector—in an array of neutron detectors mounted to one face of the spacecraft. These new detectors enable efficient neutron detection capability in a small package, making them ideal for use on a CubeSat platform.

Impact: LunaH-Map will produce maps of hydrogen abundance with the highest spatial resolution ever acquired by a neutron detector from orbit, and will demonstrate the capability of a CubeSat platform to acquire neutron counts from planetary surfaces. Understanding the distribution of hydrogen on the surface of the moon will help NASA plan future missions to the moon, especially missions that will land on the surface. Knowing the location and volume of ice deposits will also be vital to future moon missions that plan to make use of in situ resources—for example, a human mission to the moon. LunaH-Map will also use a highly efficient ion propulsion system to maneuver itself from the Space Launch System (SLS) into a stable lunar orbit, and finally a science mapping orbit. LunaH-Map and Lunar IceCube will be the first two interplanetary CubeSats to demonstrate this technology in space on a small spacecraft platform.

Orbit ground track shown in red for the entire 60 (Earth) day LunaH-Map science phase:141 passes over target area initially (and periodically) centered on Shackleton Crater withclose-approach of 5 km at each perilune crossing. Yellow circle denotes LunaH-Mapaltitude of 8 km; green circle denotes LunaH-Map altitude of 12 km.

 

Status and Future Plans: LunaH-Map is one of 13 CubeSats scheduled for launch on the first integrated flight of NASA’s Space Launch System and Orion spacecraft in 2018. LunaH-Map is being designed, built, and tested at Arizona State University. Industry partners will design, build, and deliver the spectrometers for integration into the spacecraft.

Busek’s 65W iodine-fueled ion propulsion system “BIT-3,” currently scheduled to fly onthe LunaH-Map and Lunar IceCube missions.

 

Sponsoring Organization: PSD provides funding for the LunaH-Map effort via the PICASSO program. PI, Craig Hardgrove, resides at Arizona State University. STMD’s SBIR program provides funding for technology development related to the detector component of the spectrometer to Radiation Monitoring Devices, Inc. and the ion propulsion system to Busek Co. Inc.

Master Image: 

Search for stellar survivor of a supernova explosion [heic1707]

3 April 2017 - 9:07am

Astronomers have used the NASA/ESA Hubble Space Telescope to observe the remnant of a supernova explosion in the Large Magellanic Cloud. Beyond just delivering a beautiful image, Hubble may well have traced the surviving remains of the exploded star's companion.

James Webb telescope: Hubble successor set for yet more tests

3 April 2017 - 9:06am

The spectacular James Webb Space Telescope is bound next for the giant Apollo testing chamber.

Most of Mars' air was 'lost to space'

3 April 2017 - 9:06am

The gas argon tells scientists that the atmosphere at Mars was once as thick as it is on Earth today.

Planetary science: Reckless orbiting in the Solar System

30 March 2017 - 8:59am

Planetary science: Reckless orbiting in the Solar System

Nature 543, 7647 (2017). doi:10.1038/543635a

Authors: Helena Morais & Fathi Namouni

Planets and most asteroids revolve around the Sun in the same direction. But an asteroid that shares Jupiter's orbit has been revolving in the opposite direction for about a million years. See Letter p.687

A retrograde co-orbital asteroid of Jupiter

30 March 2017 - 8:58am

A retrograde co-orbital asteroid of Jupiter

Nature 543, 7647 (2017). doi:10.1038/nature22029

Authors: Paul Wiegert, Martin Connors & Christian Veillet

Recent theoretical work in celestial mechanics has revealed that an asteroid may orbit stably in the same region as a planet, despite revolving around the Sun in the sense opposite to that of the planet itself. Asteroid 2015 BZ509 was discovered in 2015, but with too much uncertainty in its measured orbit to establish whether it was such a retrograde co-orbital body. Here we report observations and analysis that demonstrates that asteroid 2015 BZ509 is indeed a retrograde co-orbital asteroid of the planet Jupiter. We find that 2015 BZ509 has long-term stability, having been in its current, resonant state for around a million years. This is long enough to preclude precise calculation of the time or mechanism of its injection to its present state, but it may be a Halley-family comet that entered the resonance through an interaction with Saturn. Retrograde co-orbital asteroids of Jupiter and other planets may be more common than previously expected.

Astronomy: Landslides cause comet eruptions

30 March 2017 - 8:57am

Astronomy: Landslides cause comet eruptions

Nature 543, 7647 (2017). doi:10.1038/543593c

The collapse of cliffs on comets can create plumes of gas and dust, which contribute to comets' characteristic tails.Such outbursts are frequent, but their cause has been unclear. Maurizio Pajola at the NASA Ames Research Center in Moffett Field, California, and his colleagues analysed

Planetary science: Titan's electrified dunes

30 March 2017 - 8:57am

Planetary science: Titan's electrified dunes

Nature 543, 7647 (2017). doi:10.1038/543592b

The dunes of Saturn's largest moon, Titan, may be held together by static electricity.Grains of sand acquire electrostatic charge as they rub against each other, but on Earth this effect is generally negligible because gravity and a high density of heavy silicate particles minimize

The coldest place in the universe marks a double stellar grave

30 March 2017 - 8:55am

New observations finally reveal why an odd planetary nebula is so chilly: two stars met their end in close quarters

Backwards asteroid shares an orbit with Jupiter without crashing

30 March 2017 - 8:54am

A rare retrograde asteroid has been spotted in Jupiter's orbital zone - and nudges from the giant planet may have kept it stable there for a million years

NASA to Preview ‘Grand Finale’ of Cassini Saturn Mission

30 March 2017 - 8:53am
Portal origin URL: NASA to Preview ‘Grand Finale’ of Cassini Saturn Mission Portal origin nid: 399048Published: Wednesday, March 29, 2017 - 12:57Featured (stick to top of list): noPortal text teaser: NASA will hold a news conference at 3 p.m. EDT Tuesday, April 4, at the agency’s Jet Propulsion Laboratory (JPL) in Pasadena, California, to preview the beginning of Cassini's final mission segment, known as the Grand Finale, which begins in late April. The briefing will air live on NASA Television and the agency’s website.Portal image: NASA's Cassini spacecraft will make 22 orbits of Saturn during its Grand Finale, exploring a totally new regionScience Categories: Solar System