Astro Blog

By Dennis Normile , Science.  Excerpt: The BepiColombo mission is now scheduled to arrive at the tiny and little-studied planet in November 2026, 11 months behind schedule. The European Space Agency (ESA), which developed the $1.8 billion BepiColombo in cooperation with the Japan Aerospace Exploration Agency (JAXA), said in a 2 September statement that the  mission's scientific objectives will not be affected  by the delay. Meanwhile, the revised trajectory has the craft passing 165 kilometers from Mercury's surface on 4 September during a gravity assist flyby. The encounter, 35 kilometers closer than originally planned, provides an opportunity to test instruments and study the interaction between the solar wind and the planet's magnetic field. Scientists are planning to make the most of the flyby, starting up 10 of the mission's 16 instruments. ...Launched in October 2018,  BepiColombo is carrying two probes , ESA's Mercury Planetary Orbiter, with 11 instruments, ...

https://eos.org/articles/mercury-isnt-alone-in-orbit-and-scientists-dont-know-why By Jure Japelj , Eos/AGU.  Excerpt: A cloud of dust traces the innermost planet’s orbital path. By all accounts, it shouldn’t be there. ...In a new study  published  in the  Planetary Science Journal,  scientists tried to trace the genesis of Mercury’s dust. And although they still don’t know how this improbable cloud formed, they do know that it probably has a different origin story than the one escorting our own planet. ...Earth’s dust ring formed from the immense cloud of dust, called a zodiacal or interplanetary dust cloud, that pervades the space between planets. ...Earth and Venus are massive enough to stall migrating dust, but Mercury is not. That close to the Sun, phenomena including solar winds, solar light, and strong magnetic fields should, quite literally, kick the dust up, and Mercury isn’t large enough to trap the celestial debris in its gravitational pull. ...Using ...

Source:   NASA Excerpt: After extraordinary science findings and technological innovations,  ...NASA’s MErcury Surface, Space ENvironment, GEochemistry, and Ranging (MESSENGER) spacecraft launched in 2004 to study Mercury will impact the planet’s surface, most likely on April 30, after it runs out of propellant. ...Although Mercury is one of Earth’s nearest planetary neighbors, little was known about the planet prior to the MESSENGER mission. “For the first time in history we now have real knowledge about the planet Mercury that shows it to be a fascinating world as part of our diverse solar system,” said John Grunsfeld, associate administrator for the Science Mission Directorate at NASA Headquarters in Washington.  ...One key science finding in 2012 provided compelling support for the hypothesis that Mercury harbors abundant frozen water and other volatile materials in its permanently shadowed polar craters. Data indicated the ice in Mercury's polar regions, if ...

Source:    NASA RELEASE: 11-330 Excerpt: ...Scientists for decades had puzzled over whether Mercury had volcanic deposits on its surface. New data show a huge expanse of volcanic plains surrounding the planet's north polar region. These continuous smooth plains cover more than six percent of the planet's total surface. The deposits appear typical of flood lavas, or huge volumes of solidified molten rock similar to those found in the northwest United States. "If you imagine standing at the base of the Washington Monument, the top of the lavas would be something like 12 Washington Monuments above you," said James Head of Brown University…. Scientists also have discovered vents or openings measuring up to 16 miles (25 kilometers) across that appear to be the source of some of the large volume of very hot lava that has rushed across Mercury's surface….   www.nasa.gov/home/hqnews/2011/sep/HQ_11-330_Messenger_Images.html

Source:    NASA RELEASE: 11-186 Excerpt: Data from MESSENGER [MErcury Surface, Space ENvironment, GEochemistry, and Ranging spacecraft], the first spacecraft to orbit Mercury, is giving scientists important clues to the origin of the planet and its geological history  ...Two decades ago, Earth-based radar images showed deposits thought to consist of water ice and perhaps other ices near Mercury's north and south poles ... preserved on the cold, permanently shadowed floors of high-latitude impact craters. MESSENGER is testing this idea by measuring the floor depths of craters near Mercury's north pole. For more information about the mission, visit: http://www.nasa.gov/messenger messenger.jhuapl.edu/news_room/details.php  

Source:   NASA Scientists     Excerpt: Planetary scientists once thought Earth was an oasis in a dry solar system, as early missions to our neighbors revealed desert-like conditions on the Moon, Mars, and Mercury. ...Missions in recent years have overturned our view of a dry solar system, returning mounting evidence of ample water from a vast array of locations. …Jupiter's moon Europa  …Comets ... Mars  ...The Moon, ... Even Mercury.... solarsystem.nasa.gov/yss/display.cfm

Source:   Kenneth Chang, New York Times Excerpt: On Wednesday NASA showed off some of the first pictures taken by its Mercury Messenger spacecraft, which is to spend at least a year photographing, measuring and studying the smallest planet. Mercury has been seen close up… in half a dozen flybys…: three by the Mariner 10 in the 1970s and three by the Messenger in the last three years. But now …planetary scientists will be able to get their first long look at the smallest of the eight planets. The day side of Mercury can broil at 800 degrees Fahrenheit; the night side drops to minus 300 degrees. Particularly intriguing, scientists say, are the shadows in craters near Mercury’s poles. There, the Sun never shines, and in the frigidity, some scientists expect that the Messenger will find frozen water.   www.nytimes.com/2011/03/31/science/space/31mercury.html

Source:   NASA MESSENGER Mission News Excerpt: “Achieving Mercury orbit was by far the biggest milestone since MESSENGER was launched more than six and a half years ago,” says MESSENGER Project Manager Peter Bedini, of APL. “This accomplishment is the fruit of a tremendous amount of labor on the part of the navigation, guidance-and-control, and mission operations teams, who shepherded the spacecraft through its 4.9-billion-mile [7.9-billion-kilometer] journey.” For the next several weeks, APL engineers will be focused on ensuring that MESSENGER’s systems are all working well in Mercury’s harsh thermal environment. messenger.jhuapl.edu/news_room/details.php  

Source:  Kenneth Chang, New York Times Excerpt: Images suggest that Mercury was volcanically active well into its middle age, given that it formed 4.5 billion years ago with the rest of the solar system. www.nytimes.com/2010/07/20/science/20mercury.html

Source:   NASA RELEASE: 10-170   Excerpt: WASHINGTON -- The first spacecraft designed by NASA to orbit Mercury is giving scientists a new perspective on the planet's atmosphere and evolution. ... MESSENGER conducted a third and final flyby of Mercury in September 2009 ... revealed the first observations of ion emissions in Mercury's exosphere, or thin atmosphere … and evidence of younger volcanic activity than previously recorded. ...During its first two flybys of Mercury, the spacecraft captured images confirming that the planet's early history was marked by pervasive volcanism. The spacecraft's third flyby revealed … cratered plains … younger than the basin they fill… the youngest volcanic deposits … yet found on Mercury,"  ... observations suggest the planet spanned a much greater duration volcanism than previously thought, perhaps extending well into the second half of solar system history."  www.nasa.gov/home/hqnews/2010/jul/10-170_Messenger_New_...