2015 is an amazing year for space missions (not that 2014 has been a bad one) – plenty of them under way and expectations are high for the results they are going to deliver.
New Horizons: if 2014 has been the Year of the Comet thanks to Rosetta, 2015 is going to be the Year of Pluto – when the fastest spacecraft ever launched, New Horizons, will perform a fly-by of the ex-ninth, now dwarf planet (maybe on its way to become a planet again) passing within 10,000 km (6,200 mi) in mid-July.
As of April 30, 2015, the spacecraft was at this position, travelling at 14.57 km/s (32,600 mph) relative to the Sun and at 13.77 km/s relative to Pluto:
- 0.60 AU (90,000,000 km; 56,000,000 mi) from Pluto
- 32.29 AU (4.831×109 km; 3.002×109 mi) from the Sun
- 31.86 AU (4.766×109 km; 2.962×109 mi) from Earth.
In the meantime we have just started receiving direct imagery, with a first view of the surface features of Pluto and Charon.
“As we approach the Pluto system we are starting to see intriguing features such as a bright region near Pluto’s visible pole, starting the great scientific adventure to understand this enigmatic celestial object. (….) As we get closer, the excitement is building in our quest to unravel the mysteries of Pluto using data from New Horizons.” (NASA Press Release, 29 April 2015).
The first ever images showed Pluto’s poles. “Because Pluto is tipped on its side (like Uranus), when observing Pluto from the New Horizons spacecraft, one primarily sees one pole of Pluto, which appears to be brighter than the rest of the disk in all the images. Scientists suggest this brightening in Pluto’s polar region might be caused by a “cap” of highly reflective snow on the surface. The “snow” in this case is likely to be frozen molecular nitrogen ice. New Horizons observations in July will determine definitively whether or not this hypothesis is correct.” (NASA, April, 30, 2015)
Dawn: In another space exploration’s milestone, the spacecraft Dawn, after having reached Vesta in 2011, has in March 2015 entered Ceres’ orbit, becoming the first to have orbited two extraterrestrial targets and discovering a series of surprising details, such as the brilliant white spots on the surface.
“This dwarf planet was not just an inert rock throughout its history. It was active, with processes that resulted in different materials in different regions. We are beginning to capture that diversity in our colour images.” (NASA, April, 13 2015).
Rosetta: The hero of 2014, Rosetta hangs on and keeps following 67P/Churyumov-Gerasimenko comet in its fast approach to the Sun – through its perihelion (August 2015) and until the end of the mission. Its work is not without issues – just a few weeks ago it experienced troubles due to its proximity to the comet – but we can still expect some more discoveries from the ESA’s spacecraft. You can always track the comet (and Rosetta’s) position checking this website, or at the hashtag #LivingWithAComet.
Cassini: One of most successful (and longest) missions ever launched, after having made fundamental discoveries and sent back incredible videos, Cassini keeps delivering.
Right now the most promising results come from its exploration of Saturn’s moons – Titan’s being the most obvious. Recent news have communicated important findings related to Enceladus and its icy tendrils. “As the supply lanes for Saturn’s E ring, the tendrils give us a way to ascertain how much mass is leaving Enceladus and making its way into Saturn orbit. (…) So, another important step is to determine how much mass is involved, and thus estimate how much longer the moon’s sub-surface ocean may last.” (NASA, April, 14 2015).