Institute of Astronomy

Astronomy News

Hubble rounds up the first worlds we’ll check for alien life

24 November 2016 - 9:24am

The space telescope is set to spend hundreds of hours over the next year picking out the perfect planet for its successor, the James Webb Space Telescope, to probe in earnest

Honour for software writer on Apollo moon mission

24 November 2016 - 9:22am

Barack Obama awards medal to Margaret Hamilton to recognise role in sending humankind into space.

Schiaparelli: Esa gives update on Mars crash investigation

24 November 2016 - 9:22am

The European Space Agency's preliminary report into the Schiaparelli crash on Mars confirms the probe became confused about its altitude.

Two-year extensions confirmed for ESA's science missions

23 November 2016 - 9:26am
ESA's Science Programme Committee (SPC) has today confirmed two-year mission extensions for nine scientific missions in which the Agency is participating. This secures their operations until the end of 2018.

A dash of hydrogen and methane could have kept Mars warm

23 November 2016 - 9:25am

The Red Planet’s thin atmosphere of carbon dioxide can’t retain enough heat for water to flow on the planet, but new calculations suggest how it was once warmer

Is new talk of interstellar drive too good to be true?

21 November 2016 - 8:10am

Speculation about the EM drive, a proposed fuel-free, physics-busting starship engine, is back but is it still strictly for dreamers, wonders Geraint Lewis

Not so warped

21 November 2016 - 8:04am

From tractor beams to warp drive, sci-fi has inspired serious real-life research.

Icy surprises at Rosetta's comet

18 November 2016 - 8:51am

As Rosetta's comet approached its most active period last year, the spacecraft spotted carbon dioxide ice – never before seen on a comet – followed by the emergence of two unusually large patches of water ice.

Tidal evolution of the Moon from a high-obliquity, high-angular-momentum Earth

18 November 2016 - 8:49am

Tidal evolution of the Moon from a high-obliquity, high-angular-momentum Earth

Nature 539, 7629 (2016). doi:10.1038/nature19846

Authors: Matija Ćuk, Douglas P. Hamilton, Simon J. Lock & Sarah T. Stewart

In the giant-impact hypothesis for lunar origin, the Moon accreted from an equatorial circum-terrestrial disk; however, the current lunar orbital inclination of five degrees requires a subsequent dynamical process that is still unclear. In addition, the giant-impact theory has been challenged by the Moon’s unexpectedly Earth-like isotopic composition. Here we show that tidal dissipation due to lunar obliquity was an important effect during the Moon’s tidal evolution, and the lunar inclination in the past must have been very large, defying theoretical explanations. We present a tidal evolution model starting with the Moon in an equatorial orbit around an initially fast-spinning, high-obliquity Earth, which is a probable outcome of giant impacts. Using numerical modelling, we show that the solar perturbations on the Moon’s orbit naturally induce a large lunar inclination and remove angular momentum from the Earth–Moon system. Our tidal evolution model supports recent high-angular-momentum, giant-impact scenarios to explain the Moon’s isotopic composition and provides a new pathway to reach Earth’s climatically favourable low obliquity.

Pluto 'has slushy ocean' below surface

18 November 2016 - 8:45am

Pluto may harbour a slushy water ocean beneath its most prominent surface feature, known as the "heart".

'Roundest known space object' identified

18 November 2016 - 8:44am

Astronomers claim to have discovered the roundest object ever measured in nature.

Asteroid strike made 'instant Himalayas'

18 November 2016 - 8:44am
The asteroid impact that wiped out the dinosaurs moved rock huge distances as it dug out a crater in what is now the Gulf of Mexico, scientists say.

Mystery cosmic radio blasts come with side of gamma rays

18 November 2016 - 8:40am

Fast radio bursts have baffled astronomers for nearly 10 years. Now we’ve seen one accompanied by energetic gamma rays, meaning they’re more energetic than we thought

Spacecraft could taste Europa’s sea by sampling its atmosphere

15 November 2016 - 9:26am

The moon’s watery plumes may vent into space from its hidden ocean. Now we have a way to study these jets weeks after a blast and maybe spot signs of life

Beagle Mars probe probably didn’t crash, new analysis shows

14 November 2016 - 9:44am

New research shows that the lander deployed at least three - perhaps all four - of its solar panels after touching down on the planet

'Supermoon' viewers to get closest glimpse since 1948

14 November 2016 - 9:42am
Skywatchers are preparing for a "supermoon" after the moon made its closest approach since 1948.

Virtual Milky Way

11 November 2016 - 9:19am

ESA’s Gaia mission is surveying stars in our Galaxy and local galactic neighbourhood in order to build the most precise 3D map of the Milky Way and answer questions about its structure, origin and evolution.

Launched in 2013, Gaia has already generated its first catalogue of more than a billion stars – the largest all-sky survey of celestial objects to date.

To achieve its scientific aims, the spacecraft operates in an ultra-high-precision pointing mode, and to enable the flight control team to monitor spacecraft performance, Gaia regularly reports to the ground information about its current attitude and the stars that have been observed.

These engineering data have been accumulated over 18 months and combined to create a ‘map’ of the observed star densities, from which a beautiful and ghostly ‘virtual image’ of our magnificent Milky Way galaxy can be discerned, showing the attendant globular clusters and Magellanic clouds.

A ghostly image of our Milky Way galaxy derived from spacecraft orientation data Credit: ESA

The intensity scale of this map represents star density derived from the engineering data representing star density. Where there are more stars, as in the Galactic centre, the map is brighter; where there are fewer, the map is darker. The map includes brightness data corresponding to several million stars.

More information on Gaia operations

Editor’s note: On 21 November, at 16:00 CET, the Gaia mission team will host a live ‘Ask Me Anything’ chat. Details will be posted via ESA social media channels later.

How to see biggest supermoon in almost 70 years

11 November 2016 - 9:17am

A supermoon is due on 14 November and meaning the Moon will be the biggest and brightest since 1948 - but what is a supermoon?

WFIRST coronagraph: Imaging Giant Exoplanets Around Nearby Stars

11 November 2016 - 9:16am

Technology Development: The Wide-Field Infrared Survey Telescope (WFIRST) is the highest-ranked recommendation for a large space mission in the NRC 2010 decadal survey, New Worlds, New Horizons (NWNH) in Astronomy and Astrophysics. The WFIRST coronagraph instrument (CGI) will be the first high-contrast stellar coronagraph in space. It will enable WFIRST to respond to the goals of NWNH by directly imaging and spectrally characterizing giant exoplanets similar to Neptune and Jupiter, and possibly even super-Earths (extrasolar planets with a mass higher than Earth’s but lower than our Solar System’s ice giants, Neptune and Uranus), around nearby stars. The WFIRST CGI includes both a Shaped Pupil Coronagraph (SPC) and a Hybrid Lyot Coronagraph (HLC). All three of WFIRST’s CGI technology milestones for 2015 were passed successfully.

Measured milestone contrasts for the HLC (middle) and SPC (left) in a vacuum testbed in2015, where the milestone target contrast of 10-8 average in the dark hole (the annularand wedge-shaped regions, respectively) was achieved for both coronagraphs, as plannedand on schedule.

 

First, the HLC demonstrated a raw contrast (speckle/star intensity ratio) of 10-8, using a 10% bandwidth filter in visible light (550 nm), in a static environment. Second, the SPC achieved the same milestone under the same conditions. For both the HLC and SPC, the figure above shows excellent average contrast (blue-green) over most of the field of view, and slight turn-up (red) at the inner and outer radii, as expected. The third milestone was accomplished when the Low Order Wavefront Sensing and Control (LOWFS) subsystem achieved its goal of providing sensing of pointing jitter and control at the 0.4 milli-arc-second rootmean- square (RMS) level, which will keep a target star sufficiently centered on the coronagraph star-blocking mask, when the WFIRST telescope experiences pointing drift and jitter.

Pupil-plane reflective mask for the SPC, 24-mm diameter, black silicon on mirror (left).Image-plane reflective mask for the back-up technology Phase Induced AmplitudeApodization Complex Mask Coronagraph (PIAA-CMC) coronagraph, 155-μm diameter,raised elements on silicon (center). Image-plane transmitting mask for HLC, 100-μmdiameter, raised dielectric and metal on glass (right). All masks were fabricated in theMicro-Devices Lab (MDL) at the Jet Propulsion Laboratory (JPL).

 

Impact: With achievement of these milestones, NASA is a major step closer to being confident that WFIRST will be able to directly image planets and dust disks around nearby stars. There are at least 15 radial-velocity exoplanets that both coronagraphs will be able to image in their dark hole regions, in a few hours integration time each. The WFIRST coronagraph will enable scientists to see these exoplanets directly for the first time, and the images will be in their true colors (using some of the other color filters in the CGI). A simulation is shown in the figure on page 9, where the blocked star is hidden inside the annulus; a planet is seen at about 5 o’clock, and the star is assumed to have no zodiacal dust around it (left) or a strong dust cloud (right).

Status and Future Plans: WFIRST successfully completed its Mission Concept Review in December 2015, in preparation for its Phase-A start the following January (which was also successful). The CGI is baselined as a technology demonstration instrument on WFIRST; it does not drive mission requirements beyond those needed for the Wide Field Instrument. However, with one year of allocated observing time out of a six-year mission, NASA expects that it will achieve breakthrough science, and will demonstrate key technology elements for follow-up missions, the next of which could be aimed at finding habitable Earth-like planets around nearby stars.

Simulation of expected image with CGI on WFIRST of a planet (at about 5 o’clock) with nozodiacal dust cloud (left) and with a zodiacal dust cloud (right).

 

Sponsoring Organization: This coronagraph technology is jointly funded by the Astrophysics Division’s SAT program, in partnership with the NASA Space Technology Mission Directorate (STMD). NASA JPL currently leads the coronagraph development effort, and key contributions of the coronagraph team have been provided by three former SAT PIs: Jeremy Kasdin at Princeton University, John Trauger at NASA JPL, and Olivier Guyon at the University of Arizona.

Master Image: 

Sculpting Solar Systems

10 November 2016 - 9:23am
Sharp new observations have revealed striking features in planet-forming discs around young stars. The SPHERE instrument, mounted on ESO’s Very Large Telescope, has made it possible to observe the complex dynamics of young solar systems — including one seen developing in real-time. The recently published results from three teams of astronomers showcase SPHERE’s impressive capability to capture the way planets sculpt the discs that form them — exposing the complexities of the environment in which new worlds are formed.