Mercury | Universe Today

Even though the MESSENGER spacecraft experienced a "hiccup" during its third and final flyby of Mercury on Sept. 29, scientists are still pleased and surprised by the data garnered. The spacecraft went into safe mode, shutting down temporarily because of a power system switchover during a solar eclipse as it approached the planet and only half of the expected observations were carried out. But the new data – combined with observations from the two previous flybys — provide an almost complete view of Mercury's surface and offer new, unexpected scientific findings. "Although the area viewed for the first time by spacecraft was less than 350 miles across at the equator, the new images reminded us that Mercury continues to hold surprises," said principal investigator Sean Solomon.
Read more…

Filed under: Mercury | 8 Comments »

If you want to REALLY see Mercury up close and personal, take a look at this absolutely HUGE mosaic of the planet. It was put together by Jason Perry, who actually works with the Cassini mission but in his spare time stitched together 66 images from the MDIS narrow angle camera from the MESSENGER mission's second flyby of Mercury in October 2008, along with some data from the Mariner 10 mission in the 1970's. The full file is 20 MB, with a resolution of 0.6 kilometers (0.37 miles) per pixel. What fun! —for us, that is. It took Perry four days just to set up his software, according to Emily Lakdawalla at the Planetary Society Blog.

Enjoy!

Filed under: Mercury | 6 Comments »

More new images were released today from the MESSENGER spacecraft's third flyby of Mercury. I asked astrophysicist Dr. Jeff Goldstein (doctorjeff on Twitter), (who was on hand at the mission operations center to blog and Tweet about the flyby) which image the science team found most intriguing, and he replied that it was really hard to tell, as they were oohing and aahing at every image! But one of the most interesting was this shot of a bright spot on the planet closest to the sun. MESSENGER's Narrow Angle Camera also saw this spot during the spacecraft's second Mercury flyby on October 6, 2008, but the bright feature was just on the planet's limb (edge) from the spacecraft's vantage point. This time, however, the geometry of MESSENGER's flyby provided a better look at this feature. Surprisingly, at the center of the bright halo is an irregular depression, which may have formed through volcanic processes. Color images from MESSENGER's Wide Angle Camera reveal that the irregular depression and bright halo have distinctive color. This area will be of particular interest for further observation during MESSENGER's orbital operations starting in 2011.
Read more…

Filed under: Mercury | 2 Comments »

The MESSENGER spacecraft went into safe mode just before its closest approach of Mercury on Sept. 29. Although the instruments were taking data as the spacecraft came near the planet during this third flyby of the mission, after going into safe mode, no further data or pictures were obtained. This means the expected science investigations from the flyby were not executed. However, as Emily Lakdawalla pointed on in the Planetary Blog, the most important purpose of this flyby was the last gravity assist that will allow MESSENGER to enter orbit in 2011, and to that end, the flyby was a complete success. Additionally, the images taken during the approach are of the 5% of Mercury that was previously unseen, as in the image above of this unnamed basin. See more images from the approach below.
Read more…

Filed under: Mercury, Missions | 7 Comments »

Next week, on September 29, 2009 the MESSENGER spacecraft will fly by Mercury for the third and final time, looking at areas not seen before in the two previous passes. The spacecraft will pass 141.7 miles above the planet’s rocky surface, receiving an a final gravity assist that will enable it to enter orbit about Mercury in 2011. With more than 90 percent of the planet’s surface already imaged, the team will turn its instruments during this flyby to specific features to uncover more information about the planet closest to the Sun.
Read more…

Filed under: Mercury | 1 Comment »

The MESSENGER mission has been revealing more of Mercury's surface, including plenty of craters so interesting that geologists have been christening them with names.

The International Astronomical Union released new names for 16 impact craters this week. All of the craters were discovered during the flyby in October, which is also when MESSENGER snapped these images–five minutes apart–as it left. Read more…

Filed under: Astronomy, Mercury | 1 Comment »

Compared to Earth, Mercury doesn't have much of an atmosphere.  The smallest rocky planet has weak surface gravity, only 38% that of Earth.  And the scorching-hot daytime surface temperatures of 800 degrees Fahrenheit (approximately 450 degrees Celsius) should have boiled away any trace of Mercury's atmosphere long ago.  Yet recent flybys of the MESSENGER spacecraft clearly revealed Mercury somehow retains a thin layer of gas near its surface.   Where does this atmosphere come from?

Read more…

Filed under: Astronomy, Mercury, Solar System | 31 Comments »

Making good on its promise to work together with other space agencies, NASA has selected two science instruments that will fly on board European Space Agency (ESA) spacecraft, one heading to Mars on the ExoMars rover, the other to Mercury with the BepiColombo orbiter. "The selections will further advance our knowledge of these exciting terrestrial planets," said Jim Green, director of NASA's Planetary Division at NASA Headquarters in Washington. "The international collaboration will create a new chapter in planetary science and provide a strong partnership with the international science community to complement future robotic and human exploration activities."
Read more…

Filed under: Mars, Mercury, esa | 3 Comments »

Even though Mercury looks like the Moon at first glance, scientists from the MESSENGER mission say it's becoming apparent that Mercury is an amazingly dynamic planet, and is actually more like Mars. For example, before this mission, scientists weren't sure if volcanism even existed on Mercury, but from the spacecraft's two flybys, they now know it is a very important part of the planet's history. Additional new findings from the second flyby of Mercury in October 2008 show that the planet’s atmosphere, magnetosphere, and geological past are all characterized by much greater levels of activity than scientists first suspected.

And by the way, isn't this a stunning picture of an impact basin? It's one of the new discoveries from MESSENGER.
Read more…

Filed under: Mercury | 124 Comments »

Scientists from the MESSENGER mission to Mercury discussed today the results from the spacecraft's October 6 flyby of the closest planet to the sun. The probe has produced several science firsts and is returning hundreds of new photos and measurements of the planet's surface, atmosphere and magnetic field. The images show a battered surface, and we now have pictures and data of parts of Mercury's surface that have never been examined by a spacecraft. "The region of Mercury's surface that we viewed at close range for the first time this month is bigger than the land area of South America," said Sean Solomon, principal investigator and director of the Department of Terrestrial Magnetism at the Carnegie Institution of Washington. "When combined with data from our first flyby and from Mariner 10, our latest coverage means that we have now seen about 95 percent of the planet."
Read more…

Filed under: Mercury | 7 Comments »

Here's the first image from MESSENGER's flyby of Mercury on Monday. The bright crater just south of the center of the image is Kuiper, which has been seen before on images from the Mariner 10 mission in the 1970s. But most of this image, to the east, or right of Kuiper, toward the limb of Mercury is new territory for human eyes – at least in optical views. The image was taken by the Wide Angle Camera as MESSENGER was departing from the planet, and are among the first spacecraft views of that portion of Mercury’s surface. Most striking are the large pattern of rays that extend from north to south, almost along the entire face of Mercury. Amazing! This extensive ray system appears to emanate from a relatively young crater newly imaged by MESSENGER, providing a view of the planet distinctly unique from that obtained during MESSENGER’s first flyby.

2nd Update: (9:40 am CDT) More images!

Update: (8:50 am CDT) See 2nd image released below:

Read more…

Filed under: Mercury | 9 Comments »

This morning at 4:40 am EDT, the MESSENGER spacecraft passed only 200 kilometers (124 miles) above Mercury’s surface as it made its second flyby of the mission. Now, the spacecraft is speeding away from Mercury, continuing its science observations for about 20 hours following closest approach. This flyby should provide the first global perspective of Mercury, as, if all went well, we should have images in total covering about 95 percent of the planet. "This second flyby will show us a completely new area of Mercury's surface, opposite from the side of the planet we saw during the first," said Louise M. Prockter, scientist for the mission.

If you're looking for images and data from the flyby here, sorry to disappoint, but data will be transmitted to Earth only after the completion of all science observations. So, for now, even the MESSENGER science team has to wait. But scientists are already eagerly exploring the optical navigation images acquired just prior to the flyby. Shown here is a Narrow Angle Camera (NAC) image from the eighth and final optical navigation image set, taken about 14.5 hours before the flyby’s closest approach.
Read more…

Filed under: Mercury | 2 Comments »

Scientists from the MESSENGER mission continue to analyze the data from the spacecraft's first flyby of Mercury on January 14, 2008. Initial data about the planet's gravity field grabbed the science team's attention, as the actual gravity data differed from predictions based on the Mariner 10 flyby in 1975. Any unknowns in Mercury's gravity will provide challenges for the spacecraft's navigation during the next flyby in October, and especially when MESSENGER goes into orbit of Mercury in 2011. This in turn could affect quality and detail of science observations. "There indeed are residuals that we have not yet been able to explain fully," said Ralph McNutt, MESSENGER Project Scientist. "While we believe we have resolved possible extraneous effects, we continue to work those as well."
Read more…

Filed under: Mercury | 3 Comments »

No, not that kind of snow, but scientists say deep inside the planet Mercury, iron “snow” forms and falls toward the center of the planet, much like snowflakes form in Earth’s atmosphere and fall to the ground. The movement of this iron snow could be responsible for Mercury’s mysterious magnetic field, and Mercury may be the only body in our solar system where this occurs.
Read more…

Filed under: Mercury | 2 Comments »

Scientists have expressed their concern that the Solar System may not be as stable as it seems. Happily orbiting the Sun, the eight planets (plus Pluto and other minor planets) appear to have a high degree of long-term gravitational stability. But Jupiter has a huge gravitational influence over its siblings, especially the smaller planets. It appears that the long-term prospects for the smallest planet are bleak. The huge gravitational pull of Jupiter seems to be bullying Mercury into an increasingly eccentric death-orbit, possibly flinging the cosmic lightweight into the path of Venus. To make things worse, there might be dire consequences for Earth…
Read more…

Filed under: Jupiter, Mercury | 63 Comments »