Artist's conception of Juno coming near Earth on a planned flyby Oct. 9, 2013. Credit: NASA
Every so often, engineers send a spacecraft in Earth’s general direction to pick up a speed boost before heading elsewhere. But sometimes, something strange happens — the spacecraft’s speed varies in an unexpected way. Even stranger, this variation happens only during some Earth flybys.
“We detected the flyby anomaly during Rosetta’s first Earth visit in March 2005,” stated Trevor Morley, a flight dynamics specialist at the European Space Agency’s European Space Operations Centre in Darmstadt, Germany.
“Frustratingly, no anomaly was seen during Rosetta’s subsequent Earth flybys in 2007 and 2011. This is a real cosmic mystery that no one has yet figured out.”
The phenomenon has been noticed in several spacecraft (both from ESA and NASA) since 1990. NASA’s NEAR asteroid spacecraft in January 1998 had the largest change, of 13 millimeters (0.5 inches) a second. The smallest variations, with NASA’s Saturn-bound Cassini in 1999 and Mercury-pointing MESSENGER in 2005, were below the threshold of measurement.
ESA won’t even speculate on what’s going on. “The experts are stumped,” the agency says in a press release.
Those experts, however, do have some ideas on how to track that down. ESOC plans to watch Juno’s flyby using a 35 meter deep-space dish in Malargüe, Argentina, as well as a 15-meter dish in Perth, Australia
“The stations will record highly precise radio-signal information that will indicate whether Juno speeds up or slows down more or less than predicted by current theories,” ESA states.
What do you think is going on? Let us know in the comments!
An oblique view of pyroclastic vents on Mercury via MESSENGER
Here on Earth we’re used to seeing volcanoes as towering mountains with steam-belching peaks or enormous fissures oozing lava. But on Mercury volcanic features often take the form of sunken pits surrounded by bright reflective material. They look like craters from orbit but are more irregularly-shaped, and here we have a view from MESSENGER of a cluster of them amidst a rugged landscape that stretches all the way to the planet’s limb.
The image above shows a group of pyroclastic vents on Mercury, located just north and east of the 180-mile (290-km) -wide, double-ringed Rachmaninoff crater. The vents lie in the center of a spread of high-reflectance material, sprayed out by ancient eruptions. This bright blanket of material stands out against Mercury’s surface so well, it has even been spotted in Earth-based observations!
An older vent can be seen at the bottom right, looking like a crater but with non-circular walls. North is to the left.
So why do Mercury’s volcanoes look so different than Earth’s? Planetary scientist David Blewett from Johns Hopkins University Applied Physics Laboratory explains:
“Volcanism on Mercury (and also the Moon) appears to have been dominated by flood lavas, in which large quantities if highly fluid (low-viscosity) magma erupts and flows widely to cover a large area. In this type of eruption, no large ‘volcano’ edifice is constructed,” David wrote in an email. “The lunar maria and many of Mercury’s smooth plains deposits were formed in this manner.”
“On both the Moon and Mercury there are also examples of explosive activity in which eruptions from a vent showered the surroundings with pyroclastic material (volcanic ash),” he added. “The vents and bright pyroclastic halos seen near Rachmaninoff on Mercury are examples, as well as numerous ‘dark mantle deposits’ on the Moon.”
The discovery and investigation of vents like these is extremely valuable to scientists, as they provide information on Mercury’s formation, composition, and the nature of volatiles in its interior. (Plus the oblique angle is very cool! Makes you feel like you’re flying along with MESSENGER over Mercury’s surface.)
See below for a wider view of the region and context of the placement of these vents to Rachmaninoff.
MESSENGER image of Rachmaninoff crater obtained in September 2009
This elevated rise on Mercury resembles a vaguely humanoid shape
You’ve all heard of the “face on Mars” and the “man in the Moon” — well I guess this would be the “man on Mercury!” And I feel like I’ve seen him somewhere before…
“Oh, they’ve encased him in carbonite. He should be quite well protected.”
In yet another instance of the phenomenon known as pareidolia, it’s hard not to see the vaguely human shape in this image of Mercury’s surface, acquired by the MESSENGER spacecraft in July 2011. But what looks like a person with upraised arms (resembling, the team suggests, a certain carbonite-encased space smuggler) is really an ancient block of surface crust that juts from the floor of Mercury’s vast Caloris basin — likely the remnants of harder material predating the basin-forming impact 3.9 billion years ago. The low angle of sunlight from the west helps to highlight the surface shapes.
The image above shows an area 96 km (59.7 mi.) across.
If Jabba really wanted to keep his favorite wall decoration safe, perhaps he should have put it on Mercury…
The MESSENGER team celebrates 1,000 featured images of the innermost planet!
It’s been nearly two and a half years since the NASA-sponsored MESSENGER mission entered orbit around Mercury — the first spacecraft ever to do so — and today the MESSENGER team celebrated the 1,000th featured image on the mission site with a mosaic of discovery highlights, seen above.
“I thought it sensible to produce a collage for the 1,000th web image because of the sheer volume of images the team has already posted, as no single picture could encompass the enormous breadth of Mercury science covered in these postings,” explained MESSENGER Fellow Paul Byrne, of the Carnegie Institution of Washington. “Some of the images represent aspects of Mercury’s geological characteristics, and others are fun extras, such as the U.S. Postal Service’s Mercury stamp. The ‘1,000’ superimposed on the collage is a reminder of the major milestone the team has reached in posting 1,000 featured images — and even a motivation to post 1,000 more.”
See the very first image MESSENGER obtained from orbit below:
The Mercury Dual Imaging System (MDIS) team has posted a new image to the MESSENGER website approximately once per business day since March 29, 2011, when this first image of Mercury’s surface obtained from orbit was made public.
“During this two-year period, MESSENGER’s daily web image has been a successful mechanism for sharing results from the mission with the public at large,” said Nancy Chabot, MDIS Instrument Scientist at the Johns Hopkins University Applied Physics Laboratory (APL). Chabot has been leading the release of web images since MESSENGER’s first flyby of Mercury in January 2008.
“The first image I released was this one, as MESSENGER approached Mercury for the mission’s first Mercury flyby,” said Chabot. “Mercury was just a small crescent in the image, but it was still very exciting for me. We were obtaining the first spacecraft images of Mercury since Mariner 10 transmitted its final image in 1975, and this was just the beginning of the flood of images that followed.”
One of the first spacecraft images of Mercury since Mariner 10 transmitted its final image in 1975
The herculean effort involved in posting a new image every business day was made possible by a small team of scientists in addition to Chabot and Byrne, including APL’s David Blewett, Brett Denevi, Carolyn Ernst, Rachel Klima, Nori Laslo, and Heather Meyer.
“Creating images and captions for the MESSENGER Image Gallery has been fun and interesting,” Blewett said. “Working on a Gallery release gives me a chance take a break from my regular research and look all around Mercury’s surface for an image that the general public might find to be engaging from a scientific, artistic, or humorous perspective (and sometimes all three!).”
“The posting of the 1,000th image of Mercury on our web gallery is a wonderful benchmark, but there’s much more to come,” adds MESSENGER Principal Investigator Sean Solomon of Columbia University’s Lamont-Doherty Earth Observatory. “MESSENGER’s altitude at closest approach is steadily decreasing, and in a little more than six months our spacecraft will be able to view Mercury at closer range than ever before with each orbit. Stay tuned!”
Image credits: NASA/Johns Hopkins University Applied Physics Laboratory/Carnegie Institution of Washington
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 entered orbit about Mercury on March 17, 2011 (March 18, 2011 UTC).
Hi-res targeted MESSENGER image of the interior of Tyagaraja crater (north is to the right).
Here’s a rather interesting view from orbit around the innermost planet: Mercury’s Tyagaraja crater, the interior of which is seen here in an oblique-angled image acquired by the MESSENGER spacecraft on November 12, 2011 (and released August 16, 2013.)
This view looks west across the northern portion of the 97-kilometer (60-mile) -wide crater, and shows some of its large central peaks, terraced walls, and bright erosion features called hollows that are spread across a wide swath of its interior.
First seen by MESSENGER in 2011, hollows are thought to indicate an erosion process unique to Mercury because of its composition and close proximity to the Sun. The lack of craters within hollows seems to indicate that they are relatively young features… in fact, they may be part of a process that continues today.
This image was acquired as a high-resolution targeted observation. Targeted observations are images of a small area on Mercury’s surface at resolutions much higher than the 200-meter/pixel morphology base map.
Enhanced-color image of Tyagaraja crater acquired on Sept. 29, 2011. Its large hollow field is highlighted.
Tyagaraja is named after Kakarla Tyagabrahmam, an 18th-century composer of classical Indian Carnatic music.
Prepare yourself for some goosebumps. The Mercury spacecraft MESSENGER took this series of images of Earth eight years ago today as it swung by the planet (again) en route to its final destination.
Few humans have seen the Earth as an entire orb. Only a handful of missions, all in the Apollo era, have ventured beyond low Earth orbit. The people who traveled furthest were Jim Lovell, Fred Haise and Jack Swigert during Apollo 13, when their spacecraft (which had been crippled by an explosion) looped around the moon on the way home.
MESSENGER is happily traveling around Mercury these days and recently recorded a cool series of images showing the planet as a colorful, spinning sphere. The spacecraft — the first to do an extended stay around that planet — has shown scientists a lot of things, including the discovery of water ice and organics.
The face of Earth aimed toward Cassini during imaging on July 19, 2013
So along with the rest of the world, you smiled. You waved. You went outside on July 19, wherever you were, and looked upwards and out into the solar system knowing that our robotic representative Cassini would be capturing a few pixels’ worth of photons bouncing off our planet when they eventually reached Saturn, 900 million miles away. But did Cassini actually capture any photons coming from where you were? The image above will tell you.
Assembled by the Planetary Habitability Laboratory at the University of Puerto Rico at Arecibo (where the enormous 305-meter radio telescope is located) this image shows what side of Earth was facing Cassini when its “pale blue dot” images were obtained, at approximately 22:47 UTC (Cassini time.)
Didn’t make it into Cassini’s photo? That’s ok… maybe MESSENGER had already caught you earlier that very same day:
The view of Earth seen by MESSENGER from Mercury on July 19, 2013
Before Cassini took its images — several hours before, in fact — the MESSENGER spacecraft was holding some photo shoots of its own from 61 million miles in the other direction!
The image above shows the side of Earth that was facing Mercury on the morning of July 19, 2013, when MESSENGER was acquiring images in our direction during a hunt for any possible satellites of the innermost planet.
Earth was as bright (-4.8 magnitude) as the maximum brightness of Venus at the moment the image was taken from Mercury.
Of course, in both series of images specific details of our planet can’t be made out — Earth was barely more than a pixel in size (regardless of any bloom caused by apparent brightness.) Clouds, countries, continents, oceans… the entire population of our world, reduced to a single point of light — a “mote of dust suspended in a sunbeam.”
For both portrayals, high-resolution black and white images from the GOES East and Meteosat meteorological satellites were combined with color information from NASA Visible Earth to generate true-color images of our planet as it would have looked to each respective imaging spacecraft… if they had the impossibly-precise optics to resolve Earth from such distances, of course.
But it’s ok that they don’t… we can still use our imaginations.
Earth from the geostationary weather satellite GOES East on July 19, 2013 at 5 PM EST. This is approximately the view that Cassini would have had of Earth during imaging.
Image credits: PHL @ UPR Arecibo, NASA/Johns Hopkins University Applied Physics Laboratory/Carnegie Institution of Washington, NERC Satellite Station, Dundee University, Scotland. Thanks to Prof. Abel Méndez (PHL/UCR) for the heads-up on these.
A look at what Cassini's point of view will be at the time of the #WaveAtSaturn event. Image courtesy Mike Smithwick and Distant Suns.
You’ve hopefully heard about the chance to have your picture taken this Friday – along with the rest of humanity – by the Cassini spacecraft, currently about 1 billion km away as it orbits Saturn. But now another spacecraft has joined in on the fun.
Inspired in part by the Cassini team, scientists from the MESSENGER mission at Mercury realized their upcoming orbital parameters has Earth coincidentally in the crosshairs of its cameras as it takes images to search for natural satellites around Mercury on July 19 and 20. So we’ve got not one, but TWO spacecraft to smile at, pose for, and generally be on good behavior as they take pictures of planet Earth. Here’s when you should be smiling and waving:
MESSENGER will be taking images at 11:49, 12:38, and 13:41 UTC (4:49 a.m., 5:38 a.m. and 6:41 a.m. PDT or 7:49 a.m., 8:38 a.m. and 9:41 a.m. EDT, or) on both days, July 19 and 20. Parts of Earth not illuminated in the Cassini images, including all of Europe, the Middle East and Central Asia, will appear illuminated in the MESSENGER images. MESSENGER’s images also will take a few days to process prior to release, the team said.
The image taken from the Saturn system by NASA’s Cassini spacecraft will occur between 21:27 and 21:47 UTC (2:27 and 2:42 PDT, 5:27 and 5:42 p.m. EDT) on Friday, July 19. Cassini will be nearly 900 million miles (nearly 1.5 billion kilometers) away from Earth. NASA is encouraging the public to look and wave in the direction of Saturn at the time of the portrait and share their pictures via the Internet.
The ‘Wave at Saturn” event will be the first time Earthlings have had advance notice that their picture will be taken from interplanetary distances. Credit: NASA/JPL-Caltech
Also, at the exact time the Cassini spacecraft is snapping pics of Earth, the Slooh Space Camera will be snapping images of Saturn – live and in true color – with live broadcast team. Their feed starts at 2:30 PM PDT / 5:30 PM EDT / 21:30 UTC with live views of Saturn from the Canary Islands.
Astronomers Without Borders is also sponsoring a special Saturn Observing Program, and they are encouraging people and organizations to either organize a special observing event for July 19 (you can register it as an official event here) or to attend an event near you. You can find TDTES events here. This can be a full-blown observing event with telescopes, or just an excuse to get together with friends to go out and look at Saturn in the night sky.
The different colors in this MESSENGER image of Mercury indicate the chemical, mineralogical, and physical differences between the rocks that make up the planet’s surface. Credit: NASA/Johns Hopkins University Applied Physics Laboratory/Carnegie Institution of Washington.
The MESSENGER mission has now mapped the entire surface of planet Mercury — and this is the first time this has even been done. MESSENGER is the first spacecraft to be in orbit of Mercury, and has been there since 2011, with a couple of flybys starting in 2008 as it slowly looped its way into orbit. The seven scientific instruments and radio science investigation on the spacecraft have provided an entirely new view of the planet.
This colorful view of Mercury is, of course, not what Mercury would look like to the human eye. It was created by using images from the color base map imaging campaign during MESSENGER’s primary mission. These colors enhance the chemical, mineralogical, and physical differences between the rocks that make up Mercury’s surface, allowing scientists to figure out all the different minerals that are on the planet’s surface.
The complete map of Mercury was completed and released in February of 2013, and is made of thousands of images taken by MESSENGER. The spinning video map shows Mercury as, really, we’ve not seen it before, and it is fun to watch features like large rayed craters and basins spin into view.
The MESSENGER team explained the colors:
Young crater rays, extending radially from fresh impact craters, appear light blue or white. Medium- and dark-blue areas are a geologic unit of Mercury’s crust known as the “low-reflectance material”, thought to be rich in a dark, opaque mineral. Tan areas are plains formed by eruption of highly fluid lavas. The giant Caloris basin is the large circular tan feature located just to the upper right of center of the image.
You can see an image of the other side of Mercury here, and the complete gallery of science images and mosaics here.
Planets conjunction over Mont-Saint-Michel, Normandy, France on May 26. Credit: Thierry Legault -
www.astrophoto.fr
Triple planets (Venus/Jupiter/Mercury) conjunction over Mont-Saint-Michel, Normandy, France on May 26. Credit: Thierry Legault – www.astrophoto.fr Update: See expanded Conjunction astrophoto gallery below[/caption]
The rare astronomical coincidence of a spectacular triangular triple conjunction of 3 bright planets happening right now is certainly wowing the entire World of Earthlings! That is if our gallery of astrophotos assembled here is any indication.
Right at sunset, our Solar System’s two brightest planets – Venus and Jupiter – as well as the sun’s closest planet Mercury are very closely aligned for about a week in late May 2013 – starting several days ago and continuing throughout this week.
And, for an extra special bonus – did you know that a pair of spacecraft from Earth are orbiting two of those planets?
Have you seen it yet ?
Well you’re are in for a celestial treat. The conjunction is visible to the naked eye – look West to Northwest shortly after sunset. No telescopes or binoculars needed.
Triple conjunction shot on May 26 from a mile high in Payson,Az. 4 second exposure, ISO200, Canon 10D, 80mm f/5 lens. Credit: Chris Schur- http://www.schursastrophotography.com
Just check out our Universe Today collection of newly snapped astrophoto’s and videos sent to Nancy and Ken by stargazing enthusiasts from across the globe. See an earlier gallery – here.
Throughout May, the trio of wandering planets have been gradually gathering closer and closer.
On May 26 and 27, Venus, Jupiter and Mercury appear just 3 degrees apart as a spectacular triangularly shaped object in the sunset skies – which
adds a palatial pallet of splendid hues not possible at higher elevations.
And don’t dawdle if you want to see this celestial feast. The best times are 30 to 60 minutes after sunset – because thereafter they’ll disappear below the horizon.
The sky show will continue into late May as the planets alignment changes every day.
On May 28, Venus and Jupiter close in to within just 1 degree.
And on May 30 & 31, Venus, Jupiter and Mercury will form an imaginary line in the sky.
Triple planetary conjunctions are a rather rare occurrence. The last one took place in May 2011. And we won’t see another one until October 2015.
Indeed the wandering trio are also currently the three brightest planets visible. Venus is about magnitude minus 4, Jupiter is about minus 2.
While you’re enjoying the fantastic view, ponder this: The three planets are also joined by two orbiting spacecraft from humanity. NASA’s MESSENGER is orbiting Mercury. ESA’s Venus Express is orbiting Venus. And NASA’s Juno spacecraft is on a long looping trajectory to Jupiter.
Send Ken you conjunction photos to post here.
And don’t forget to “Send Your Name to Mars” aboard NASA’s MAVEN orbiter- details here. Deadline: July 1, 2013
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Learn more about Conjunctions, Mars, Curiosity, Opportunity, MAVEN, LADEE and NASA missions at Ken’s upcoming lecture presentations:
June 4: “Send your Name to Mars” and “CIBER Astro Sat, LADEE Lunar & Antares Rocket Launches from Virginia”; Rodeway Inn, Chincoteague, VA, 8:30 PM
June 11: “Send your Name to Mars” and “LADEE Lunar & Antares Rocket Launches from Virginia”; NJ State Museum Planetarium and Amateur Astronomers Association of Princeton (AAAP), Trenton, NJ, 730 PM.
May 25 conjunction over Malta. Canon 450D with a 55mm. lens and an exposure of 1/2 second at ISO 200 on a tripod. Credit: Leonard Ellul-MercerMay 26 triple conjunction from Warwick, NY snapped from Canon Rebel, 100mm – 300mm lens. Credit: Pietro CarboniTriple conjunction from Hondo, Texas taken with a Nikon D800 @ ISO 400 and a 2 second exposure with a Nikon 300mm Lens at F/4. Credit: Adrian New Sunset conjunction with fast moving clouds on May 26 through 10 x 50 binoculars from a seashore town -Marina di Pisa, Tuscany, Italy. Credit: Giuseppe Petricca
Caption: Taken on 2013-05-23 from Salem, Missouri. Canon T1i, Nikkor 105mm lens. 297 1/4s at 1s interval. Images assembled by QuickTime Pro. Credit: Joseph Shuster
May 26 sunset conjunction from Princeton, NJ. Credit: Ken Kremer -kenkremer.comTriple Planetary conjunction over Onset MA. Shot with a Nikon d7000 1/200 f 4 iso 100 at 110mm. Credit: Phillip DamianoPanoramic view over Almada City and Lisbon at the Nautical Twilight, with the Full moon rising above the Eastern horizon (right side of the image), while at the same time but in the opposite direction, the planets Venus, Mercury and Jupiter, are aligned in a triangle formation, setting in the Western horizon (left side of the image).In this panoramic picture is also visible the smooth light transition in the sky, with the end of Nautical Twilight and the beginning of Astronomical Twilight (almost night), at right. Facing to North, is visible the great lighted Monument Christ the King and at the left side of it, part of the 25 April Bridge that connects Almada to Lisbon. Canon 50D – ISO200; f/4; Exp. 1,6 Sec; 35mm. Panoramic of 10 images with about 200º, taken at 21h42 in 25/05/2013. Credit: Miguel Claro – www.miguelclaro.comThe triple conjunction of Venus, Mercury and Jupiter as seen over an Arizona desert landscape. Credit and copyright: Robert Sparks.Jupiter, Venus and Mercury triple conjunction seen here reflecting off Chatsworth Lake in Chatsworth, NJ. Jupiter (on the left) was 2.4° from Mercury (upper-right in the sky) and 2.0° from Venus (bottom right in the sky), while Venus and Mercury were 1.9° apart. Venus was at 2.6° altitude. Canon EOS 6D, 105 mm focal length, 1.3 seconds, f/6.3, ISO 800. Credit: Joe Stieber – sjastro.org/Triple conjunction on May 27 with WBZ radio towers south east of Boston. Hampton Hill, Hull, MA. Nikon D3x -iso200- 1.3 sec.at f2.8. Credit: Richard W. Green
