News • MissioN Update space shorts ESA selects PLATO The European Space Agency Mission update has selected PLATO – Planetary Transits and Oscillations of stars – as its third medium- class (M3) space mission. The mission will identify and study thousands of exoplanetary systems, with an emphasis on Earth-size planets and super- Earths in the habitable zone of their parent star. PLATO will use 34 separate small telescopes and cameras to search for Downloaded from https://academic.oup.com/astrogeo/article/55/2/2.7/251523 by guest on 23 September 2021 exoplanets using the transit technique; together with ground- based radial velocity data, this will indicate the mass, radius, age and probably composition of exoplanets. The spacecraft will operate from the L2 position and is expected to be launched in 2024. http://sci.esa.int/plato Rosetta awakes European comet scientists are relieved to have the comet- chasing spacecraft Rosetta back online after its 31-month shutdown. On 20 January this year the spacecraft’s signal reached Earth, confirming that it had restarted its instruments on time and the mission to Comet 67P/Churyumov- Fresh impact spotted on Mars Gerasimenko would continue. This image from the HiRISE (High Resolution Imaging Science Experiment) camera on NASA’s Mars As befits a modern spacecraft, Reconnaissance Orbiter shows a fresh impact crater at 3.7°N, 53.4°E. The image was taken on 19 November the successful awakening was 2013, in response to changes in appearance identified with the orbiter’s Context Camera between July 2010 and announced with a tweet of May 2012 – limiting the date of the impact. The crater is about 30 m across and surrounded by a rayed blast zone “Hello, World”. Now the mission that, in this enhanced image, appears blue because the red dust that normally covers Mars’s surface has been team has extensive instrument blown away and ejecta spread over the surface, including over some dunes. Ejected material has travelled up testing on the spacecraft and to 15 km from the crater. More than 200 craters measuring over 3.9 m across form on Mars each year, but few of its Philae lander to prepare it them look as spectacular as this. (NASA/JPL-Caltech/Univ. of Arizona) for the rendezvous in August http://1.usa.gov/1crpgTV 2014. The first images of the target comet should come in May and the landing is expected the NASA Exoplanet Archive. closer to the surface of the planet, in November. Rosetta will stay Kepler confirms Among the new discoveries, four eventually reaching altitudes below with the comet into 2015 through are less than 2.5 times the size of 350 km, from where the Narrow perihelion in August. 715 new planets Earth and orbit in their star’s habit- Angle Camera will acquire images http://bit.ly/1fvE0a0 In February the Kepler mission team able zone. One of these orbits a star with pixel scales between 2 and announced 715 confirmed planets that is half the Sun’s size and 5% of its 20 m. Higher resolution images are Juno halfway there orbiting 305 stars, using a statistical brightness; the planet may be a gas or already coming in, with an image of NASA’s Juno mission has passed framework to search out multiple- water world, depending on its mass. a crater 15 km across revealing hol- the halfway mark on its journey planet systems within exoplanet sys- http://www.nasa.gov/kepler lows that appear to have formed in to Jupiter, where it will arrive tems discovered by Kepler between the wall of the crater. They are shal- in 2016. Mission scientists have May 2009 and March 2011. low, irregular, bright depressions also completed commissioning This technique relies on the distri- MESSENGER hits whose formation may involve loss of of Juno’s nine instruments. bution of multiple-planet systems volatile material. As the spacecraft The final checks were made within Kepler data, confirming mul- 200 000 images moves closer to the planet towards on the JADE (Jovian Auroral tiple-planet systems while excluding MESSENGER’s second extended the end of its mission, scientists can Distributions Experiment) false positives such as those arising mission has been so successful that expect to see a lot more of them. instrument, which is sensitive to from companion stars. This batch the spacecraft has now returned more http://messenger.jhuapl.edu high temperatures and could not of planets brings the total number of than 200 000 images of the surface of be fully commissioned during exoplanets confirmed by the Kepler Mercury, a considerable bonus over 2011, nor during the Earth fly-by mission to 961, among 3601 planet the “at least 1000” envisaged in the Cassini: Saturn’s in 2013. All instruments are candidates (and 2165 eclipsing binary original mission proposal. working as expected. stars); the total number of confirmed The second extended mission dancing aurora http://1.usa.gov/NeXVhy planets stands at 1690, according to involves the spacecraft orbiting ever NASA’s Cassini spacecraft provided A&G • April 2014 • Vol. 55 2.7 News • MissioN Update space shorts Mars in the morning The longest-serving Mars orbiter, NASA’s Mars Odyssey, has changed track a little, moving towards a morning- daylight orbit, to be achieved by November 2015. The goal is data on changing ground temperatures after sunrise and sunset across the planet. No Mars orbiter since the 1970s has flown on a path that allows imaging of the ground in morning daylight, preferring Downloaded from https://academic.oup.com/astrogeo/article/55/2/2.7/251523 by guest on 23 September 2021 instead less hazy afternoon lighting. But now detailed Mars images suggest that warm season flows exist and that carbon dioxide ice may thaw and A global geological map of Ganymede lead to geysers. http://mars.jpl.gov/odyssey Ganymede has played a part in astronomy since Galileo observed it orbiting Jupiter more than 400 years ago. Now the best imagery from NASA’s Voyager 1 and 2 spacecraft in 1979 and the Galileo orbiter between 1995 Lunar impact spotted and 2003 have been combined to produce a global mosaic of the icy surface (right) and a geological map (left). The largest observed meteorite The map is the work of a group led by Geoffrey Collins of Wheaton College, USA, who used the relative ages impact on the Moon took place of features such as impact craters and grooves and ridges arising from tectonic activity to set up a geological on 11 September 2013, on the timescale. Broadly, darker areas are older, lighter regions younger; in detail, the team identified three major Mare Nubium. The impact periods in the history of the moon. Initially, impact cratering dominated, then tectonic activity was significant. produced a bright flash detected More recently, geological activity as a whole decreased. The synthesis of relative age data over the moon as a by an automated telescope whole allowed researchers to compare hypotheses about the development of the icy surface. Cryovolcanism system, MIDAS (the Moon – eruption of water and ice from volcanoes – turns out to be very rare on Ganymede, for example. (USGS Impacts Detection and Analysis Astrogeology Science Center/Wheaton/NASA/JPL-Caltech) System) led by Prof. Jose Maria http://1.usa.gov/1mLj53x Madiedo from the University of Huelva, and Dr Jose L Ortiz from the Institute of Astrophysics suggests that magnetic reconnection of Andalusia. The researchers may lead to auroral storms, as it does estimate the impactor as a at Earth, and sheds light on the heat- 400 kg body between 0.6 and ing mechanisms of the atmospheres 1.4 m across, making a 40 m of the giant planets. crater; the results are published http://1.usa.gov/1gGEtmm in Monthly Notices of the RAS. http://bit.ly/1eJxWET Trojan Hektor’s Jade Rabbit not roving The status of China’s lunar rover exotic orbit Yutu – “jade rabbit” – remains The largest Trojan asteroid, Hektor, in doubt, although engineers and its moon have a complex orbit restored normal signal reception that suggests that they are Kuiper functions after a second lunar belt objects captured during reshuf- night. China was only the fling of the giant planets. third nation to achieve a soft 1: This Cassini image shows a bright curtain aurora above Saturn on 29 Trojans orbit 60° ahead or behind landing on the Moon when the November 2010, over a depth of about 1500 km, together with faint star Jupiter; Hektor’s unnamed moon Chang’e-3 lander and Yutu rover trails arising from the spacecraft’s movement. (NASA/JPL-Caltech/SSI) was discovered in 2006 by a team touched down in December led by Franck Marchis of the SETI 2013. Yutu uses solar power and a 3D view of Saturn’s aurora in April gen and oxygen atoms and mol- Institute. It took eight years of shuts down during the lunar and May of 2013, at the same time ecules, Saturn’s are purple at high observations with the W M Keck night. After the first fortnight as Hubble Space Telescope observa- levels and red lower in the atmo- Observatory to determine the orbit. of dormancy, problems with tions of the northern aurora. Cas- sphere and the light comes domi- The 12 km moon orbits the 250 km movement and communication sini, orbiting Saturn at close range nantly from excited hydrogen. asteroid every three days at a dis- arose; many assumed that the (about six Saturn radii) collected The Cassini ultraviolet imag- tance of 600 km in an ellipse inclined rover had failed completely. data at infrared, visible and ultra- ing spectrometer (UVIS) data were almost 45° with respect to the aster- After the second night it carried violet wavelengths, while the HST especially interesting because they oid’s equator.