MESSENGER to Mercury
Published on Jan 2, 2008 at 6:52 pm.
2 Comments.
Filed under planets, space exploration.
The MESSENGER spacecraft was launched on its way to Mercury in August of 2004. It is now just about to pass by that desolate planet (in about a week and a half). This will be the first mission to Mercury since Mariner 10, which was launched towards Mercury in November of 1973, flying past the planet three times in 1974 and 1975.
Oh, and my caps lock is is not stuck whenever I type MESSENGER. The spacecraft’s name is an acronym for the MErcury Surface, Space Environment, GEochemistry and Ranging spacecraft. I think that NASA really likes to do acronyms now-a-days. And, this particular acronym as also an allusion to the Roman god Mercury, who was the messenger of the gods in mythology. Of course, this means that the name is supposed to be all capitalized, and that is a bit of a pain. Also, it is technically a bit wrong. It should not be geochemistry because the “geo” part refers to Earth. The Greek equivalent of the Roman deity Mercury is Hermes. So, instead of geochemistry, it should actually be hermechemistry. Of course, that would make the acronym MESSENHER, which is rather silly.
The MESSENGER craft is shaped rather like a rectangular box 1.42 by 1.85 meters and 1.27 meters tall. Flying as close to the Sun as Mercury, the spacecraft is exposed to intense solar heating. In fact, without any protection from the Sun, the temperature of the spacecraft would get hot enough to destroy the electronics on board. So, a 2 meter by 2.5 meter parasol shields the spacecraft from direct sunlight. Mounted exterior to the main box of the spacecraft are imaging systems and several types of spectrometers. A magnetometer is also available to study Mercury’s magnetic field.
MESSENGER will fly past Mercury several times, with the first flyby being January 14, 2008. Eventually, on March 18, 2011, MESSENGER will go into orbit around Mercury. MESSENGER will continue its studies of Mercury while in orbit. But, Mercury won’t have to wait another three decades to be visited by another space mission. The European Space Agency plans to launch the BepiColombo mission to Mercury in 2013.
Prior to this month’s flyby by MESSENGER, no other spacecraft has been past Mercury since 1975. Though Uranus and Neptune have also only been visited by one spacecraft, the Voyager 2 spacecraft was far more capable than the Mariner 10 mission to Mercury. Also, it is much easier to point telescopes at Uranus and Neptune than at Mercury since those worlds are visible in the night sky, far from the Sun in the sky. Mercury is always very near the Sun, as seen from Earth, making observations extremely difficult. That makes Mercury one of the least studied and understood planets in the Solar System. The MESSENGER mission team hopes to change that.
There are many unanswered questions about Mercury. Mariner 10 surprised astronomers by measuring a magnetic field at Mercury. It has been presumed that a planet so small would not have a liquid metallic core capable of producing a magnetic field. However, more recent radio telescope observations of Mercury show indications that the core is indeed liquid. MESSENGER will try to unravel the mystery of Mercury’s core and magnetic field. And, speaking planetary cores, Mercury’s core may be the largest (as a percentage of the planet’s volume) of any other Solar System planet’s core. Determining if that is indeed the case, and how Mercury came to be that way, is another goal of MESSENGER. In fact, unraveling Mercury’s history as a planet is also something that MESSENGER seeks to accomplish. Less than half of Mercury was imaged by Mariner 10, so there may be a lot of surprises in store. One interesting mystery are Mercury’s lobate scarps, which are long cliffs created by thrust faults. Planetary scientists have long believed these scarps to be the result of Mercury’s interior shrinking. MESSENGER may shed light on those scarps. There have been all sorts of ideas put forward over the last three decades, but without up-close data, it is hard to determine what ideas may be right or wrong. Soon, if all goes well, we will have that up-close data.
This is a significant event, given that MESSENGER is only the second spacecraft to visit Mercury. So, expect me to do more blogging on MESSENGER and Mercury this month.
-Astroprof
Astroprof’s Page » Mercury, finally. on February 1, 2008 at 1:57 pm: 1
[…] The MESSENGER spacecraft is now nearly to Mercury. It will pass that planet tomorrow, Monday, January 13, 2008, at about 1:05pm, Central Standard Time. I have published two other postings about MESSENGER (here and here). I am not going to restate all of that, so you can go back and read them if you wish. But, I will summarize the key points. […]
Astroprof Page MESSENGER to Mercury | Shed Kits on May 26, 2009 at 11:52 pm: 2
[…] Astroprof Page MESSENGER to Mercury Posted by root 1 day 22 minutes ago (http://astroprofspage.com) Flying as close to the sun as mercury the spacecraft is exposed to intense solar heating messenger may shed light on those scarps there have been all sorts of ideas put forward over the last 1 comment to 39 messenger to mercury 39 2009 astroprof page sail Discuss | Bury | News | astroprof page messenger to mercury […]