The beginning of 2015 is off to a great start, at least when it comes to space exploration. And although one mission has ended with the crashing of NASA's MESSENGER into Mercury, another begins as New Horizon closes in on Pluto.
This week also saw a close-up view of Jupiter moon Io, showing us features we've never seen before there, as well as the first detailed image of the inside of a sunspot.
Of course, there was also the discovery of a weird exoplanet that's too big for its star, challenging what we know about how planets form.
NASA's MESSENGER crashes into Mercury.
NASA's MESSENGER mission came to an end this week when the MESSENGER spacecraft crashed into the surface of Mercury at around 8,750 mph, leaving a crater on the surface of the planet.
MESSENGER began its mission in 2004 and started orbiting Mercury in 2011. It finished its main scientific goals a few years ago, but NASA extended the mission so that the agency could continue to get new images and data on Mercury.
Thanks to MESSENGER, we figured out Mercury's surface composition and learned more about its history. We even discovered that its magnetic field is "offset from the planet's center" and confirmed that its polar caps are mostly water ice.
"Going out with a bang as it impacts the surface of Mercury, we are celebrating MESSENGER as more than a successful mission," says John Grunsfeld, associate administrator for NASA's Science Mission Directorate. "The MESSENGER mission will continue to provide scientists with a bonanza of new results as we begin the next phase of this mission--analyzing the exciting data already in the archives, and unravelling the mysteries of Mercury."
Observatory captures first detailed images of the inside of sunspots.
The New Jersey Institute of Technology's Big Bear Solar Observatory recently captured the first images of the inside of umbrae, which are the dark patches at the center of sunspots. These images unveiled magnetic fields within the structure that create the plumes of plasma that emerge from the sunspots. These new images also showed that the atmosphere above the umbrae has both hot and cold plasma jets that span over 62 miles wide.
"These data revealed to us unprecedented details of small-scale dynamics that appear to be similar in nature to what we see in other parts of the Sun," says Vasyl Yurchyshyn, the lead author of two recent articles based on the observatory's images. "There is growing evidence that these dynamic events are responsible for the heating of coronal loops, seen in ultraviolet images as bright magnetic structures that jet out from the Sun's surface. This is a solar puzzle we have yet to solve."
New Horizons sees Pluto and Charon.
As New Horizons grows closer to Pluto, it's starting to send back new images of both Pluto and its largest moon, Charon. New Horizons took the animated image above over the course of six days last month as New Horizons got closer to the dwarf planet.
These new images show a bright area on one pole of Pluto, which scientists believe is a cap of "snow" made of frozen nitrogen ice. However, we'll know more once New Horizons reaches Pluto in July.
Telescope spots lava lake on Jupiter moon Io.
The Large Binocular Telescope Interferometer (LBTI) recently captured new high-resolution images of Jupiter moon Io and it looks like one of the features on that moon is a lake of lava. We knew this volcanic feature existed there, and we even named it Loki, but until now, this feature was too small to see from a telescope based on Earth.
However, the LBTI captured Loki in all its fiery detail, revealing a surprise: two areas of volcanic activity on Io are fairly new, possibly the result of an eruption that happened only a few months ago.
Scientists discover exoplanet that's too big for its star.
A new exoplanet discovered about 500 light-years from Earth surprised scientists when they realized that it challenges everything we know about how planets form. The planet, which is about the size of Jupiter, closely orbits a small, cool M-dwarf star, one of the most common stars in the galaxy, as well as one of the least understood celestial bodies.
The discovery baffled scientists who believe the planet could have formed further outside its current orbit, but they still don't have theories about how it ended up where it is now.
"The planet has a similar mass to Saturn, but its radius is similar to Jupiter, so it's quite a puffed up planet. Because its host star is so cool it's not heating the planet up so much, it's very different from the planets we have observed so far," says researcher George Zhou from from the Australian National University. "The atmosphere of this planet will be an interesting target for future study."
[Photo Credit: NASA]