News From Space: MESSENGER and Mercury

messengerWith Curiosity’s ongoing research and manned missions being planned for Mars by 2030, it seems that the other planets of the Solar System are being sadly neglected these days. Thankfully, the MESSENGER spacecraft, which has been conducting flyby’s of Mercury since 2008 and orbiting it since 2011, is there to remind us of just how interesting and amazing the planet closest to our sun truly is.

And in recent weeks, there has been a conjunction of interesting news stories about Earth’s scorched and pockmarked cousin. The first came in March 22nd when it was revealed that of the many, many pictures taken by the satellite (over 150,000 and counting), some captured a different side of Mercury, one which isn’t so rugged and scorched.

Messenger_smooth1The pictures in question were of a natural depression located northeast of the Rachmaninoff basin, where the walls, floor and upper surfaces appear to be smooth and irregularly shaped. What’s more, the  velvety texture observed is the result of widespread layering of fine particles. Scientists at NASA deduced from this that, unlike many features on Mercury’s  ancient surface, this rimless depression wasn’t caused by an impact from above but rather explosively escaping lava from below.

In short, the depression was caused by an explosive volcanic event, which left a hole in the surface roughly 36 km (22 miles) across at its widest. It is surrounded by a smooth blanket of high-reflectance material, explosively ejected volcanic particles from a pyroclastic eruption, that spread over the surface like snow. And thanks to Mercury’s lack of atmosphere, the event was perfectly preserved.

Messenger_smooth2

Other similar vents have been found on Mercury before, like the heart-shaped depression observed in the Caloris basin (seen above). Here too, the smooth, bright surface material was a telltale sign of a volcanic outburst, as were the rimless, irregular shapes of the vents. However, this is the first time such a surface feature has been captured in such high-definition.

And then just three days later, on March 25th to be exact, Mercury began to experience its greatest elongation from the Sun for the year of 2013. In astronomy, this refers to the angle between the Sun and the planet, with Earth as the reference point. When a planet is at its greatest elongation, it is farthest from the Sun as viewed from Earth, so its view is also best at that point.

Mercury_31-03-13_0630What this means is that for the remainder of the month, Mercury will be in prime position to be observed in the night sky, for anyone living in the Northern Hemisphere that is. Given its position relative to the Sun and us, the best time to observe it would be during hours of dusk when the stars are still visible. And, in a twist which that may hold cosmic significance for some, people are advised to pay special attention during the morning of Easter Day, when the shining “star” will be most visible low in the dawn sky.

And then just three days ago, a very interesting announcement was made. It seems that with MESSENGERS ongoing surveys of the Hermian surface, nine new craters have been identified and are being given names. On March 26th, the International Astronomical Union (IAU) approved the proposed names, which were selected in honor of deceased writers, artists and musicians following the convention established by the IAU for naming features on the innermost world.

crater_names

The announcement came after MESSENGER put the finishing touches on mapping the surface of Mercury earlier this month. A good majority of these features were established at Mercury’s southern polar region, one of the last areas of the planet to be mapped by the satellite. And after a submission and review process, the IAU decided on the following names of the new craters:

Donelaitis, named after 18th century Lithuanian poet Kristijonas Donelaitis, author of The Seasons and other tales and fables.

Petofi, named after 19th century Hungarian poet Sandor Petofi, who wrote Nemzeti dal which inspired the Hungarian Revolution of 1848.

Roerich, named after early 20th century Russian philosopher and artist Nicholas Roerich, who created the Roerich Pact of 1935 which asserted the neutrality of scientific, cultural and educational institutions during time of war.

Hurley, named after the 20th century Australian photographer James Francis Hurley, who traveled to Antarctica and served with Australian forces in both World Wars.

Lovecraft, named after 20th century American author H.P. Lovecraft, a pioneer in horror, fantasy and science fiction.

Alver, named after 20th century Estonian author Betti Alver who wrote the 1927 novel Mistress in the Wind.

Flaiano, named after 20th century Italian novelist and screenwriter Ennio Flaiano who was a pioneer Italian cinema and contemporary of Federico Fellini.

Pahinui, named after mid-20th century Hawaiian musician Charles Phillip Kahahawai Pahinui, influential slack-key guitar player and part of the “Hawaiian Renaissance” of island culture in the 1970’s.

L’Engle, named after American author Madeleine L’Engle, who wrote the young adult novels An Acceptable Time, A Swiftly Tilting Planet & A Wind in the Door. L’Engle passed away in 2007.

Crater_names_August2012-580x376The campaign to name Mercury’s surface features has been ongoing since MESSENGER performed its first flyby in January of 2008. Some may recall that in August of last year, a similar process took place for the nine craters identified on Mercury’s North Pole. Of these, the names of similarly great literary, artistic and scientific contributors were selected, not the least of which was Mr. J RR Tolkien himself, author of Lord of the Rings and The Hobbit!

It’s no secret that the MESSENGER spacecraft has been a boon for scientists. Not only has it allowed for the complete mapping of the planet Mercury and provided an endless stream of high resolution photos for scientists to pour over, it has also contributed to a greater understanding of what our Solar System looked like when it was still in early formation.

Given all this, it is somewhat sad that MESSENGER is due to stand down at the end of the month, and that the next mission to Mercury won’t be until 2022 with the planned arrival of the joint ESA/JAXA BepiColombo mission. But of course, we can expect plenty of revelations and stories to emerge from all the scientific data collected on this latest trip. And I’m sure Mars will be more than willing to provide ample entertainment until 2022 comes to pass!

While we’re waiting, be sure to check out this informative video of MESSENGER’s contributions over the past few years:

Source: universetoday.com, (2), (3)

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