In this perspective view, we look northwest over the Caloris Basin, a depression about 1500 km in diameter formed several billion years ago by the impact of a large projectile into the surface of Mercury. The mountain range at the edge of the basin can be seen as an arc in the background. In the foreground, we see a set of tectonic troughs, known as Pantheon Fossae, radiating from the center of the basin outward toward the edge of the basin interior. A 41-km-diameter impact crater, Apollodorus, is superposed just slightly off from the center of Pantheon Fossae. White and red are high topography, and greens and blues are low topography, with a total height differences of roughly 4 km. The MESSENGER spacecraft was launched in 2004 and ended it's orbital operations yesterday, April 30, 2015, by impacting Mercury's surface. Background image texture is provided by the Mercury Dual Imaging System (MDIS) instrument while color corresponds to surface elevation data obtained from the Mercury Laser Altimeter (MLA) experiment, with both draped over a digital elevation model derived from MLA altimetric data. Credit: NASA/Johns Hopkins University Applied Physics Laboratory/Carnegie Institution of Washington/Goddard Space Flight Center

Speaking of signing off with a bang, because, you know, nobody really was, we might take a moment for MESSENGER:

Mission controllers at the Johns Hopkins University Applied Physics Laboratory (APL) in Laurel, Md., confirmed today [30 April 2015] that NASA’s MErcury Surface, Space ENvironment, GEochemistry, and Ranging (MESSENGER) spacecraft impacted the surface of Mercury, as predicted, at 3:26 p.m. EDT this afternoon (3:34 p.m. ground time).

MESSENGER Mission Complete: Final statistics for MESSENGER probe, which crashed into Mercury 30 April 2015 SCET.  Image from screenshot from mission page at Johns Hopkins University.Mission controllers were able to confirm the end of operations just a few minutes later at 3:40 p.m., when no signal was detected by the Deep Space Network (DSN) station in Goldstone, California, at the time the spacecraft would have emerged from behind the planet had MESSENGER not impacted the surface. This conclusion was independently confirmed by the DSN’s Radio Science team, who were simultaneously looking for the signal from MESSENGER from their posts in California.

MESSENGER was launched on August 3, 2004, and it began orbiting Mercury on March 18, 2011. The spacecraft completed its primary science objectives by March 2012. Because MESSENGER’s initial discoveries raised important new questions and the payload remained healthy, the mission was extended twice, allowing the spacecraft to make observations from extraordinarily low altitudes and capture images and information about the planet in unprecedented detail.

Last month — during a final short extension of the mission referred to as XM2′– the team embarked on a hover campaign that allowed the spacecraft at its closest approach to operate within a narrow band of altitudes, 5 to 35 kilometers above the planet’s surface. On April 28, the team successfully executed the last of seven orbit-correction maneuvers (the last four of which were conducted entirely with helium pressurant after the remaining liquid hydrazine had been depleted), which kept MESSENGER aloft for the additional month, sufficiently long for the spacecraft’s instruments to collect critical information that could shed light on Mercury’s crustal magnetic anomalies and ice-filled polar craters, among other features.

With no way to increase its altitude, MESSENGER was finally unable to resist the perturbations to its orbit by the Sun’s gravitational pull, and it slammed into Mercury’s surface at around 8,750 miles per hour, creating a new crater up to 52 feet wide.

“Today we bid a fond farewell to one of the most resilient and accomplished spacecraft ever to have explored our neighboring planets,” said Sean Solomon, MESSENGER’s Principal Investigator and Director of Columbia University’s Lamont-Doherty Earth Observatory. “Our craft set a record for planetary flybys, spent more than four years in orbit about the planet closest to the Sun, and survived both punishing heat and extreme doses of radiation. Among its other achievements, MESSENGER determined Mercury’s surface composition, revealed its geological history, discovered that its internal magnetic field is offset from the planet’s center, taught us about Mercury’s unusual internal structure, followed the chemical inventory of its exosphere with season and time of day, discovered novel aspects of its extraordinarily active magnetosphere, and verified that its polar deposits are dominantly water ice. A resourceful and committed team of engineers, mission operators, scientists, and managers can be extremely proud that the MESSENGER mission has surpassed all expectations and delivered a stunningly long list of discoveries that have changed our views not only of one of Earth’s sibling planets but of the entire inner solar system.”

(Johns Hopkins University)

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NASA Van Allen Mission Finds Another Line of Planetary Defense

A cloud of cold, charged gas around Earth, called the plasmasphere and seen here in purple, interacts with the particles in Earth's radiation belts — shown in grey— to create an impenetrable barrier that blocks the fastest electrons from moving in closer to our planet. (Image Credit: NASA/Goddard)

Ozone hole got you down?α Maybe climate change is bringing just a bit too much sunshine and wrecking the grapes in your favorite wine?β Would you cheer up if we told you it could be worse?

Meanwhile, it is hard to imagine the private sector figuring certain things just for the sake of knowing. But, yes, it turns out that things really could be worse.

Two donuts of seething radiation that surround Earth, called the Van Allen radiation belts, have been found to contain a nearly impenetrable barrier that prevents the fastest, most energetic electrons from reaching Earth.

The Van Allen belts are a collection of charged particles, gathered in place by Earth’s magnetic field. They can wax and wane in response to incoming energy from the sun, sometimes swelling up enough to expose satellites in low-Earth orbit to damaging radiation. The discovery of the drain that acts as a barrier within the belts was made using NASA’s Van Allen Probes, launched in August 2012 to study the region. A paper on these results appeared in the Nov. 27, 2014, issue of Nature magazine.

“This barrier for the ultra-fast electrons is a remarkable feature of the belts,” said Dan Baker, a space scientist at the University of Colorado in Boulder and first author of the paper. “We’re able to study it for the first time, because we never had such accurate measurements of these high-energy electrons before.”


The more we understand about how the planet protects us against the Universe at large, the more we can learn about how to protect the planet against ourselves.

Pretty straightforward, that. But if you would like to know more about the Van Allen probes, there’s a mission page for that.


α Yes, that still exists.

β A genuine challenge that is already here.

Fox, Karen C. “NASA’s Van Allen Probes Spot an Impenetrable Barrier in Space”. NASA Goddard Space Flight Center. 26 November 2014.

Astronomy and Human Progress

This morning, the National Radio Astronomy Observatory issued a press release, which in and of itself is hardly extraordinary. Its contents, however, are extraordinarily awesome:

ALMA image of the young star HL Tau and its protoplanetary disk. This best image ever of planet formation reveals multiple rings and gaps that herald the presence of emerging planets as they sweep their orbits clear of dust and gas. Credit: ALMA (NRAO/ESO/NAOJ); C. Brogan, B. Saxton (NRAO/AUI/NSF)

Astronomers have captured the best image ever of planet formation around an infant star as part of the testing and verification process for the Atacama Large Millimeter/submillimeter Array’s (ALMA) new high-resolution capabilities.

This revolutionary new image reveals in astonishing detail the planet-forming disk surrounding HL Tau, a Sun-like star located approximately 450 light-years from Earth in the constellation Taurus.

ALMA uncovered never-before-seen features in this system, including multiple concentric rings separated by clearly defined gaps. These structures suggest that planet formation is already well underway around this remarkably young star.

“These features are almost certainly the result of young planet-like bodies that are being formed in the disk. This is surprising since HL Tau is no more than a million years old and such young stars are not expected to have large planetary bodies capable of producing the structures we see in this image,” said ALMA Deputy Director Stuartt Corder.

While this photo is not about to save a life or help a man improve his intimate relations, it occasionally occurs to us to remind that astronomy is not just about fancy photos. The human species needs astronomers.

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Dreams in Martian Red

To the one, it’s always worth a try ….

Candor Chasma detail (ESA, 2008(Wanted: A man and a woman in their early to mid-50s, preferably married. Must enjoy adventure, spending long periods of time together, and sharing space—as in 501 days in a 1166-cubic-foot (33-cubic-meter) capsule and habitat. Interest in the planet Mars also a prerequisite.

Warning to applicants: You will be exposed to unprecedented risks and your long-term health could be compromised. But if the effort goes ahead and succeeds as planned, you will become the first humans in history to journey into deep space and see Mars up close.

Multimillionaire Dennis Tito, the world’s first space tourist, announced today in Washington, D.C., that his newly formed nonprofit organization has taken up the challenge of sending the first humans to Mars.

“We’ve not sent humans beyond the moon in 40 years,” Tito said at a press conference. “… And I think it’s time to put an end to that lapse.”

What’s that? A trip to Mars? With people? Marc Kaufman explains, for National Geographic News, the latest buzz in the human cosmos:

The Inspiration Mars Foundation aims to launch the mission in January 2018, when Mars and Earth are at an especially close point in their 15-year cycle. The plan is to send a man and a woman in a capsule around Mars for a flyby mission similar to the one that surveyed the moon before the Apollo landings ….Inspiration Mars

…. The Mars project is extremely ambitious, but it is at least plausible because it is simple—at least in terms of rocket science.

According to a paper Tito will present this weekend at an aerospace conference in Montana, if the launch is on target, then the spaceship will need only one rocket burn to change course. With the right trajectory, it will fly to Mars, will pass within a few hundred miles of the surface, and then will be pulled around the planet and given a gravity-assisted fling back toward Earth.

Under the current flight trajectory, the capsule would spend about ten hours within 65,000 miles of Mars.

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Ears In the Age of 3-D

Imagine, if you would, please, saying the following to your five year-old twin daughters: “I want to implant your ears on the backs of rats.”

Okay, that’s not nearly so creepy as it sounds. Nancy Shute of NPR explains:

3-D Printed EarTo make the ear, Bonassar and his colleagues scanned the ears of his twin daughters, who were 5 at the time. They used a 3-D printer to build a plastic mold based on the scan. Those printers, similar to a home inkjet, lately have also been adapted to experiment with making chocolate, guns, and even kidneys.

They then injected a soup of collagen, living cartilage cells, and culture medium. The soup congeals “like Jell-O,” Bonassar tells Shots. “All this happens quickly. You inject the mold, and in 15 minutes you have an ear ready to go.”

Well, not exactly. What they have is an ear-shaped chunk of cells that would have to be tucked under the skin on the side of the head by a plastic surgeon before it could become an ear.

To test whether their ear-mold would become living, useful ear cartilage, the researchers implanted samples under the skin on the back of laboratory rats. In three months, cartilage cells took over the collagen, making for a solid-yet-flexible chunk of cartilage that retained its precise shape and size. The results were published online in the journal PLoS One.

The technique could be a breakthrough for microtia and anotia, related birth defects in which the pinna (the part of the ear on the outside of one’s head) is underdeveloped or absent, or even the occasional missing ear resulting from an accident. Microtia occurs in the range of once every eight- to ten-thousand births, and, in truth, I have no idea what the numbers are for accidental or necessary surgical removal of pinnae.

Still, though, as with so many breakthroughs we hear about, application is most likely ten years away at a minimum.

The Upside of Education

Mini Cooper Countryman backflipA note for the kids: Study hard, and you, too, might make history someday. After all, backflipping a car is the sort of thing that takes all sorts of knowledge, namely in physics and engineering.

MINI and its stunt driver Guerlain Chicherit have done the impossible: executing the perfect “unassisted” backflip.

Using a heavily modified MINI Cooper Countryman, Chicherit, a French rally driver and avid skier, completed the stunt recently at a resort in Tignes, France.

The stunt qualifies for the unassisted certification because the ramp used by Chicherit was static ….

…. For his take-off, Chicherit used a static ramp similar to those used by skiers. With the ideal ramp breakover angle in place, the 34-year-old needed only two other things to record a successful attempt: an extremely light touch with the accelerator and a MINI with a suitably buoyant suspension setup.

Guerlain Chicheret backflipAssisted backflips? Those have been done before.

But this? Well, sure, it’s just a publicity stunt, but one must admit it’s pretty cool.