Mercury Visited By First Spacecraft In 33 Years

[FSTargetDrone]

MESSENGER has arrived:

STATUS REPORT

Date Released: Sunday, January 13, 2008

Source: Johns Hopkins University

Today, at 19:04:39 UTC (2:04:39 pm EST), MESSENGER will fly 200 kilometers (124 miles) above Mercury’s surface. As the spacecraft continues to speed toward the planet, the Narrow Angle Camera, part of the Mercury Dual Imaging System (MDIS) instrument, acquired this crescent view of Mercury. The image was taken on January 13, when the spacecraft was about 760,000 kilometers (470,000 miles) from Mercury. Mercury is about 4,880 kilometers (about 3,030 miles) in diameter, and the smallest feature visible in this image is about 20 kilometers (12 miles) across.

During the historic encounter today, extensive scientific data will be gathered. The MDIS cameras will acquire more than 1,200 images of Mercury, including images of portions of the surface never before viewed by a spacecraft. The Mercury Atmospheric and Surface Composition Spectrometer will observe Mercury's surface as well as its tenuous atmosphere. The Magnetometer will accurately measure Mercury's magnetic field, and the Energetic Particle and Plasma Spectrometer will characterize Mercury's space environment and interactions with the solar wind. The Mercury Laser Altimeter will sense surface topography along a narrow profile. The Gamma-Ray and Neutron Spectrometer and X-Ray Spectrometer will make the first measurements of Mercury’s surface elemental composition.

MESSENGER will begin to transmit the new data to Earth once all of the scientific measurements are completed, about 22 hours after the spacecraft's closest approach to Mercury. These flyby data will shed light on fundamental scientific questions related to the formation and evolution of the planet Mercury. As scientists analyze the data, the MESSENGER spacecraft will continue on its planned journey, which includes two more encounters of Mercury in October 2008 and September 2009, before entering an orbit around Mercury in March 2011.

Additional information and features from this first flyby will be available online at +http://messenger.jhuapl.edu/mer_flyby1.html, so check back frequently. Following the flyby, be sure to check for the latest released images and science results!

MESSENGER (MErcury Surface, Space ENvironment, GEochemistry, and Ranging) is a NASA-sponsored scientific investigation of the planet Mercury and the first space mission designed to orbit the planet closest to the Sun. The MESSENGER spacecraft launched on August 3, 2004, and after flybys of Earth, Venus, and Mercury will start a yearlong study of its target planet in March 2011. Dr. Sean C. Solomon, of the Carnegie Institution of Washington, leads the mission as Principal Investigator. The Johns Hopkins University Applied Physics Laboratory built and operates the MESSENGER spacecraft and manages this Discovery-class mission for NASA.

The article is a little confusing with the "Date Released" date as found, but the flyby is set for TODAY, 14 January, (at 19:04:39 UTC / 2:04:39 pm EST). Looking good so far. This mission should result in lots of new imagery, especially imagery of parts of the planet so far unseen.

[Commander 598]

Why does everyone always act like there's going to be some new and great discovery? It's a somewhat larger and sunbaked version of the moon. At best there MIGHT be something useful in the crust but it's probably not worth the effort to get it...

[FSTargetDrone]

Why does everyone always act like there's going to be some new and great discovery? It's a somewhat larger and sunbaked version of the moon. At best there MIGHT be something useful in the crust but it's probably not worth the effort to get it...

So you're saying of you don't know something interesting might be there, why bother to try? I'm not sure what you mean by a "new and great discovery" but I doubt NASA is expecting to find and photograph ruins of an ancient civilization. They sent the probe there to study the planet and its characteristics in a way previously unavailable. There may be previously unknown geological events that come to light. As the article stated, they are going to study the solar wind and its interaction with the planet. The entire purpose of the mission is, in great part, to, "shed light on fundamental scientific questions related to the formation and evolution of the planet Mercury." What do you think geologists do?

[NoXion]

Why does everyone always act like there's going to be some new and great discovery? It's a somewhat larger and sunbaked version of the moon. At best there MIGHT be something useful in the crust but it's probably not worth the effort to get it...

No, it isn't. Their internal structure and composition are quite different, and Mercury has a few surface features not found on Luna.

[FSTargetDrone]

No, it isn't. Their internal structure and composition are quite different, and Mercury has a few surface features not found on Luna.

Not only that, it possesses an atmosphere, quite unlike the Moon.

Anyway, still no images yet that I can find, but here's a bit more about the mission:

The mysteries of Mercury revealed

Posted 2h 26m ago

By Charles Q. Choi, Special to SPACE.com
Mercury is the smallest, densest and least explored planet around the sun. More than half of it is virtually unknown.

Insights into this mysterious world of extremes could shed light on how planets were made in our solar system, astronomers say.

THE MESSENGER

NASA's MESSENGER probe will be the first spacecraft to image the whole planet, making its initial flyby of Mercury Jan. 14 as part of a long process to settle into orbit.

"With MESSENGER, many of Mercury's secrets will now be revealed," said NASA's planetary science division director James Green. A list of some of these is below.

Mercury's hidden side

The only spacecraft to ever visit the solar system's innermost world — NASA's Mariner 10 — mapped less than 45% of Mercury's surface, a heavily cratered landscape. This means more than half the planet is unknown to us, save for relatively poor observations from Earth-based radars.

"We can't get cocky about what the other side of Mercury looks like. So far, every solar system body has looked very different from every other one," said Faith Vilas, director of the Multiple Mirror Telescope (MMT) Observatory at Mt. Hopkins, Ariz. "We're expecting some major surprises from it."

Ice near the sun?

On the closest planet to the sun, where temperatures can reach more than 800 degrees Fahrenheit (425 degrees Celsius), there might surprisingly be ice. Ice is highly reflective to radar, and Earth-based radar suggests deposits of frozen water might be hidden in deep, dark craters at Mercury's poles that have never seen sunlight. This water might have come gassing up from within the planet or from meteorite impacts.

MESSENGER will search for hydrogen at the permanently shadowed floors of polar craters. If the spacecraft discovers any, MESSENGER may have found ice amidst an inferno.

Is Mercury shrinking?

Mercury could be shrinking as its core slowly freezes. Pictures from Mariner 10 revealed the planet's surface appears to have buckled from within, resulting in gigantic cliffs more than a mile high and hundreds of miles long biting into Mercury. MESSENGER will look for any evidence of such crumpling on the world's hidden side and will also study the planet's metal core by analyzing that world's magnetic field.

Vulcanoids?

Do a band of small asteroids dubbed "vulcanoids" lie inward of Mercury's orbit, hidden in the glare of the sun?

MESSENGER has a chance of spotting these asteroids as it approaches Mercury, although its opportunities are limited. To keep the sun from frying it, MESSENGER hides itself behind a sunshade pointed at the sun at all times, and its scientific instruments are pointed away from the sun. Nevertheless, scientists will use MESSENGER "to chase down any hints there might still be a modern population of vulcanoids," said the MESSENGER mission's principal investigator Sean Solomon.

Where does Mercury's atmosphere come from?

Mercury's incredibly tenuous atmosphere is unstable, with gases regularly escaping the planet's weak gravity. How Mercury's atmosphere gets constantly replenished is unclear.

Researchers suspect the hydrogen and helium in Mercury's atmosphere is continuously brought there by the solar wind, the supersonic stream of charged particles from the sun. Other gases might have evaporated off Mercury's surface, seeped from inside the planet or been brought in by vaporized meteorites. MESSENGER will closely study the planet's atmosphere to pinpoint how it gets generated, Vilas said.

Why is Mercury magnetic?

A completely unexpected discovery Mariner 10 made was that Mercury possessed a magnetic field. Planets theoretically generate magnetic fields only if they spin quickly and possess a molten core. But Mercury takes 59 days to rotate and is so small — just roughly one-third Earth's size — that its core should have cooled off long ago.

To solve this mystery, MESSENGER will probe Mercury's magnetic field. There was some thinking that the field might have become inactive, but last year, scientists discovered Mercury seems to have a molten core after all, so the planet might still be actively generating a magnetic field after all.

Why all that metal?

Mercury is extraordinarily dense, leading researchers to estimate that its iron-rich core potentially makes up about two-thirds of the planet's mass, a startling figure double that of Earth, Venus or Mars. In other words, Mercury's core might take up roughly three-quarters of the world's diameter.

One theory explaining this bizarre density is that huge impacts billions of years ago might have stripped Mercury of its original surface, Vilas explained, collisions that also shifted the planet toward the sun to its current location. Another theory suggests Mercury simply formed where it now lies.

To see which theory concerning Mercury's origins might be right, MESSENGER's battery of miniaturized scientific instruments will scope out the planet's geology. Understanding how Mercury formed will shed light on how all the planets evolved, Solomon said.

[Commander 598]

Alright fine! It's partially interesting... Better use of money than sending another probe to Mars and expecting it not to tell you that it's a giant lifeless desert this time.

[Junghalli]

At best there MIGHT be something useful in the crust but it's probably not worth the effort to get it...

I think Mercury is supposed to be very rich in iron (and presumably other heavy metals), so it might be a prime spot for eventual extraterrestrial mining operations. It's closer than the asteroid belt, although it does have the disadvantage of having a gravity well.

No, it isn't. Their internal structure and composition are quite different, and Mercury has a few surface features not found on Luna.

In terms of their environments though, he's pretty much right.

[FSTargetDrone]

Alright fine! It's partially interesting... Better use of money than sending another probe to Mars and expecting it not to tell you that it's a giant lifeless desert this time.

It seems like you think this sort of exploration is wasteful unless they find something "useful." I guess it all comes down to what you feel is worthwhile. Is the space program worthwhile? That's a reasonable question to ask. I think it is, and I think robotic missions are much more useful and cost-effective at the present time than any manned missions.

By the way, there will be more missions to Mars. In fact, the Phoenix lander is on its way there, right now, scheduled to touch down in May of this year.

[Junghalli]

We're still a ways from being able to prospect planets like Mercury for useful minerals. For now think of it as getting a look at what the terrain is like.

[CaptainChewbacca]

Any sort of resource extraction from mercury would be highly problematic, especially due to the 40-odd days you'd spend on the dayside getting roasted.

[Junghalli]

You'd probably have to build the facility underground, with just a docking port for shuttles and maybe some solar panels for power on the surface.

[Commander 598]

Why is it that everyone always takes my criticism of the expensive exploration of the ass end of nowhere to confirm that it is in fact a lifeless rock as 99.999999999999999999999999% of our conclusions predicted as against the space program?

[FSTargetDrone]

Any sort of resource extraction from mercury would be highly problematic, especially due to the 40-odd days you'd spend on the dayside getting roasted.

Roasted, indeed:

Mercury's Temperature

Both the long day/night period and the exactly perpendicular rotational axis have consequences for the temperature on the surface of Mercury.

The consequence of such a long day/night period is that Mercury is the planet in the Solar System with the most extreme temperatures. During the Mercurian daytime (which lasts 88 Earth days), the temperature rises to 700 K. While on the night side, the temperature is as low 100 K.

The consequence of the rotation axis of Mercury being exactly perpendicular to its orbital plane, is that the North and South poles of Mercury always receive very spread out sunlight, as we saw before when we talked about the seasons on Earth. This means that the temperature on the Mercurian poles is rather low, since they don't receive a lot of energy from the Sun. In fact, astronomers have observed solid ice in those regions! That is unexpected!

[Gigaliel]

At best there MIGHT be something useful in the crust but it's probably not worth the effort to get it...

I think Mercury is supposed to be very rich in iron (and presumably other heavy metals), so it might be a prime spot for eventual extraterrestrial mining operations. It's closer than the asteroid belt, although it does have the disadvantage of having a gravity well.

There's also the Sol's gravity well to worry about. Much more annoying.

On an unrelated note, the areas of permanent shadow would be of much interest to any settlements do to it being waay easier to live in a cold area than a hot region. Also you can set up a heat engine with long pipes!

Finding out the details of Mercury's surface should be interesting. Now just some clear pictures of Pluto (10 years pending on that).

[GrandMasterTerwynn]

At best there MIGHT be something useful in the crust but it's probably not worth the effort to get it...

I think Mercury is supposed to be very rich in iron (and presumably other heavy metals), so it might be a prime spot for eventual extraterrestrial mining operations. It's closer than the asteroid belt, although it does have the disadvantage of having a gravity well.

There's also the Sol's gravity well to worry about. Much more annoying.

And, most annoying of all, Mercury's gravity well. Everything that comes off the surface of the planet will have to be rocketed off, or shot off via giant cannon . . . I mean mass driver. The up-front energy costs of doing this would make mining Mercury a losing proposition for virtually all applications . . . unless you were spamming the extreme inner solar system with solar powered particle accelerators to use as antimatter factories.

[CaptJodan]

Why is it that everyone always takes my criticism of the expensive exploration of the ass end of nowhere to confirm that it is in fact a lifeless rock as 99.999999999999999999999999% of our conclusions predicted as against the space program?

Because trying to expand our knowledge of the universe (or in this case, just our backyard) just isn't worth it? The fact that it isn't a world which is likely to carry any life doesn't mean it's worthless for exploration.

[Ariphaos]

You can see the pictures for yourself as they come in.

[Erik von Nein]

Aww, it's a cute little hunk of grey.

Things like this make me sort of glad I was born when I was. Sure, we've got the "fun" of global warming and peak oil happening, but we've come so far with our understanding of the universe we live in. Not just with understanding so much about our fellow planets in the Sol system but with finally finding planets (visual evidence, anyhow) in our systems. It's just awe inspiring.

[Commander 598]

Why is it that everyone always takes my criticism of the expensive exploration of the ass end of nowhere to confirm that it is in fact a lifeless rock as 99.999999999999999999999999% of our conclusions predicted as against the space program?

Because trying to expand our knowledge of the universe (or in this case, just our backyard) just isn't worth it? The fact that it isn't a world which is likely to carry any life doesn't mean it's worthless for exploration.

It costs money to explore, the same amount of money could be applied to something a lot closer to home. I'm pretty sure we actually posses the ability to mine near Earth asteroids...and if NASA wasn't completely retarded we could probably manage something a lot more useful in orbit than the glorified hamster cage of a "lab" that is the ISS...

You should know my personal views on space were spawned by Gerard O'Neill.

[Patrick Degan]

Why is it that everyone always takes my criticism of the expensive exploration of the ass end of nowhere to confirm that it is in fact a lifeless rock as 99.999999999999999999999999% of our conclusions predicted as against the space program?

Because trying to expand our knowledge of the universe (or in this case, just our backyard) just isn't worth it? The fact that it isn't a world which is likely to carry any life doesn't mean it's worthless for exploration.

It costs money to explore, the same amount of money could be applied to something a lot closer to home.

The same sort of short-sighted thinking by which critics condemn the entire idea of space science in the first place.

I'm pretty sure we actually posses the ability to mine near Earth asteroids

Actually, we don't. It's stretching the limits of current-day space technology simply to build the ISS.

and if NASA wasn't completely retarded we could probably manage something a lot more useful in orbit than the glorified hamster cage of a "lab" that is the ISS.

And if my grandmother had wheels, she'd be a wagon. Did you even bother to make yourself acquainted with present-day space engineering and spaceflight capability before coming here to spew nonsense based on capabilities which do not presently exist?

You should know my personal views on space were spawned by Gerard O'Neill.[/quote]

[FSTargetDrone]

An update from the mission site:

MESSENGER Mission News
January 14, 2008 [Post Flyby Update]
http://messenger.jhuapl.edu

MESSENGER Flyby of Mercury

At 2:04 p.m. EST MESSENGER skimmed 200 kilometers (124 miles) above the surface of Mercury in the first of three flybys of the planet. Initial indications from the radio signals indicate the spacecraft is still operating nominally. The first science data return from the flyby was received today, just minutes before the closest approach point with the planet, as planned.

“The engineers and operators at the Deep Space Network (DSN) in Goldstone, Calif., in conjunction with engineers at the Johns Hopkins University Applied Physics Laboratory (APL) in Laurel, Md., pulled off a tremendous feat, acquiring and locking onto the downlink signal from the spacecraft within seconds, providing the necessary Doppler measurements for the Radio Science team” said MESSENGER Mission Systems Engineer Eric Finnegan, of APL.“ The spacecraft is continuing to collect imagery and other scientific measurements from the planet as we now depart Mercury from the illuminated side, documenting for the first time the previously unseen surface of the planet.”

Tomorrow at noon EST, the spacecraft will turn back towards the Earth to start down-linking the on-board stored data. Measurements of this Doppler signal from the spacecraft will allow improve knowledge of Mercury’s gravity field.

Keeping a Rendezvous with Mercury

Between January 9 and 13, 2008, as the MESSENGER probe approached Mercury for its first flyby, the Narrow Angle Camera, part of the Mercury Dual Imaging System (MDIS), acquired a series of images of the planet in support of spacecraft navigation. These images have been put together as frames in a movie. The final frame of the movie has the highest spatial resolution (20 km/pixel, 12 miles/pixel) and was recorded when the spacecraft was at a distance of about 760,000 kilometers (470,000 miles) from Mercury. Mercury is about 4.880 kilometers (about 3,030 miles) in diameter.

As part of MESSENGER's flyby on January 14, MDIS will obtain high-resolution image sequences with the Narrow Angle Camera, and the Wide Angle Camera will collect images in eleven colors. The images will cover portions of the planet never before seen by spacecraft, as well as regions that were photographed by Mariner 10 in 1974 and 1975. The new data for the previously studied areas of Mercury will help scientists to interpret the data for the parts of the planet that MESSENGER will reveal for the first time.

Additional information and features from this first flyby can be viewed online at http://messenger.jhuapl.edu/mer_flyby1.html. The latest released images and science results from the flyby will be posted as they become available

So far so good! More data and pictures are due to start streaming back tomorrow.

[PeZook]

It costs money to explore, the same amount of money could be applied to something a lot closer to home. I'm pretty sure we actually posses the ability to mine near Earth asteroids...and if NASA wasn't completely retarded we could probably manage something a lot more useful in orbit than the glorified hamster cage of a "lab" that is the ISS...

It costs pocket change to send those unmanned probes out there, and we have precious little data about Mercury, while having a shitload of material about Mars and the Moon.

Besides, NASA is sending the lunar orbiter next year, and is doing preliminary work on another manned moon landing (2018, something to look forward to!) and Mars missions,plus design work on a Shuttle replacement (one that is actually economical).

What, do you think they just sit around doing nothing while the Mercury probe is on its way?

As for your assertion that we have the capability to mine asteroids...excuse me while I take a moment to laugh at you.

What, exactly, is your idea of a "near Earth asteroid"?

[Frank Hipper]

How the fuck is resource exploitation the only "useful" pursuit in space exploration, and by whose arbitrary standard?

[FSTargetDrone]

How the fuck is resource exploitation the only "useful" pursuit in space exploration, and by whose arbitrary standard?

Presumably people who don't see any obvious, immediate or "useful" return on what really is a small investment as compared to a lot of the other nonsense this country spends its money on.

By the way, speaking of a good investment, the Mars rovers are still chugging along. The 4-year anniversary of operating on the planet for the pair of them is coming up soon.

[Hawkwings]

Spirit and Opportunity are some great pieces of work. I'm happy to see that they're still continuing their mission far beyond their "warranty" lifetime.