These are the first images of Pluto’s outermost moon, Hydra, to be taken by the New Horizons spacecraft during a test its long-exposure imaging capabilities. The difference shows the moon’s movement over the few days without all of the stationary background stars. The team wasn’t expecting to see Hydra until January when New Horizons will be much closer to the Pluto system.
New Horizons is expected to flyby Pluto in mid-2015.
This map shows the distribution of HED meteorites on the surface of Vesta. HED meteorites are a type of achondrites, stony meteorites that do not contain any chondrules. Here, each color represents a different mineral: green is howardite, blue is eucrite, and red is diogenite. Areas where more than one mineral is present are either yellow for diogenitic howardite or cyan for euritic howardite. Rocks containing howardite are the most abundant on Vesta.
The map shows that the two hemispheres have different mineral distributions: the northern hemisphere is more eucritic rich while the southern hemisphere is more diogenitic rich. For reference, two craters and two basins are marked.
Launched less than a year ago, the Gaia spacecraft has discovered its first supernova. At about 500 million lightyears away, Gaia14aaa resides in the galaxy SDSS J132102.26+453223.8. By repeatedly scanning the sky, Gaia was able to detect a difference in the galaxy’s brightness over the course of one month. The Gaia team was able to identify Gaia14aaa as a Type Ia supernova by studying its spectrum.
Venus may be similar to Earth in size and mass, but there are differences between the two planets. One difference is the magnetic field. On Venus, a magnetic field isn’t generated by the planet, like Earth’s. It is actually an induced magnetosphere, a region of charged particles around the planet formed by a reaction between Venus’ ionosphere and the solar wind. New research shows that there are holes void of magnetically charged plasma in a region where such plasma is expected to be.
The holes were first noticed when the Pioneer Venus Orbiter moved around the backside of the planet back in 1978. Since then, the holes have not been detected again.
Recently, researchers studying data from the Venus Express orbiter decided to look for the holes again. They found them and realized that they were more common than initially thought, visible over a broad range of solar activity.
When the solar wind hits Venus, it wraps around the planet and a long tail extends behind it. This is what creates the magnetosphere. The Venus Express orbiter took measurements of the magnetic field strength and found variations that indicated the presence of these holes. The observations suggest that these holes are actually not just holes, but take the shape of long cylinders directed out towards space.
But what is causing these cylinders to form? In addition to the solar wind wrapping around the planet to create the magnetosphere, the researchers propose that the magnetic field lines from the solar wind is able to continue into the planet and wrap around its core, something that is also seen on the Moon. As a result, the electrically charged plasma is pushed to the sides and this is what created the two cylinders found behind the planet by the orbiters.
The planet Jupiter has 67 confirmed moons. This gives it the largest retinue of moons with “reasonably secure” orbits of any planet in the Solar System. In fact, Jupiter and its moons are like a miniature solar system with the inner moons orbiting faster than the others. Eight of Jupiter’s moons are regular satellites, with prograde and nearly circular orbits that are not greatly inclined with respect to Jupiter’s equatorial plane. The remainder of Jupiter’s moons are irregular satellites, whose prograde and retrograde orbits are much farther from Jupiter and have high inclinations and eccentricities. These moons were probably captured by Jupiter from solar orbits. There are 17 recently discovered irregular satellites that have not yet been named.
The International Astronomical Union (IAU), in partnership with Zooniverse, is organizing a citizen science project to provide new names for exoplanets and their stars. This project, NameExoWorlds, will allow users to vote on names submitted by a variety of astronomy clubs and organizations. These new names will be used in addition to their current scientific names.
Available to view now is a list of exoplanets and their host stars.
For the first time ever, scientists have gathered direct evidence of a rare Wolf-Rayet star being linked to a specific type of stellar explosion known as a Type IIb supernova. Peter Nugent of the Lawrence Berkeley National Laboratory says they caught this star – a whopping 360 million light years away – just a few hours after it exploded.
Scientists have found evidence in favor of tectonic plates on Jupiter’s moon Europa. Images from the Galileo spacecraft have shown an expanding crust similar to mid-ocean ridges on Earth that are formed by seafloor spreading.
By studying and reconstructing the surface of the moon, the scientists have found that a large amount of the surface in the northern latitudes were missing. They believe that the missing surface crust has moved underneath another section of the surface since there is a lack of mountains in the area, suggesting subduction. In addition, ice volcanoes have been found above the subduction zones.
This evidence of geological activity shows that Europa is more Earth-like than originally thought, and it is important when considering Europa as a potential habitable world.
Image: Illustration of a subduction zone on Europa. (Credit: Noah Kroese, I.NK)
Presented at the 2014 European Planetary Science Congress (EPSC) was this map of the many terrains of comet 67P/Churyumov-Gerasimenko. The surface has been broken up into different regions based on the appearance of the comet. This is just a preliminary analysis of comet 67P and a more detailed analysis will follow to study its composition. This map, along with other images, will help mission scientists to determine a landing site for the Philae lander.