MESSENGER at Rest

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).

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

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.”

(Fox)

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.

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^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.

Inquiry, Discovery, Inquiry

This is why NASA rocks:

NASA’s Lunar Reconnaissance Orbiter (LRO) has provided researchers strong evidence the moon’s volcanic activity slowed gradually instead of stopping abruptly a billion years ago.

Scores of distinctive rock deposits observed by LRO are estimated to be less than 100 million years old. This time period corresponds to Earth’s Cretaceous period, the heyday of dinosaurs. Some areas may be less than 50 million years old. Details of the study are published online in Sunday’s edition of Nature Geoscience.

“This finding is the kind of science that is literally going to make geologists rewrite the textbooks about the moon,” said John Keller, LRO project scientist at NASA’s Goddard Space Flight Center in Greenbelt, Maryland.

Science as a career is, to a certain degree, a form of job security. That is, while one might argue the idea of job security through perpetuation of the problem in certain political argumentation, the reality is that you don’t need to do that with science. That is to say, when you make a scientific discovery, you also raise a million new questions for scientists to answer.

No, really. Did you hear about the time all of five years ago that scientists at Oregon State University accidentally created a new shade of blue?

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NASA. “Release 14-284: NASA Mission Finds Widespread Evidence of Young Lunar Volcanism”. NASA.gov. 12 October 2014.

Chang, Kenneth. “By Happy Accident, Chemists Produce a New Blue”. The New York Times. 23 November 2009.

Mission: Mars—MAVEN Draws Nigh

NASA, via Facebook:

At 8 pm EDT today, MAVEN will be at a distance of 205,304,736 km (127,570,449 miles) from Earth with an Earth-centered velocity of 27.95 km/s (17.37 mi/s or 62,532 mph) and a Sun-centered velocity of 22.29 km/s (13.58 mi/s or 48,892 mph). We are now just 17 days from Mars orbit insertion on September 21st.

Having traveled a total of 678,070,879 km (421,332,902 mi) in its heliocentric transfer orbit, the MAVEN spacecraft has now covered ~95% of its total journey from Earth to #Mars.

The spacecraft is currently at a distance of 4,705,429 km (2,923,818 mi) from Mars, and 215,446,454 km (133,872,220 mi) from the Sun. One-way light time to the #MAVEN spacecraft from Earth is 11 minutes and 24 seconds.

All navigation solutions continue to produce trajectory arrival predictions that ensure a successful transition to MAVEN’s required science orbit.

This is the sort of thing that we ought to be getting excited about. The MAVEN mission is awesome.

Linkadelica

Might we suggest some light, enlightening reading?

• Dark matter?

• Or, maybe, zebra stripes around planet Earth?

• Perhaps contemplating the multiverse?

• Or puzzling over the “strangest magma on Earth”? How about extraterrestrial volcanoes?

• Would you believe the Permian-Triassic extinction was caused by microbes?

• Was that whole skydiver and meteorite thing true?

Photosynthesize This

So there is this joke we have, about how being the one government agency that routinely does its job … never mind. At any rate, NASA would have you know:

Data from satellite sensors show that during the Northern Hemisphere’s growing season, the Midwest region of the United States boasts more photosynthetic activity than any other spot on Earth, according to NASA and university scientists.

Healthy plants convert light to energy via photosynthesis, but chlorophyll also emits a fraction of absorbed light as a fluorescent glow that is invisible to the naked eye. The magnitude of the glow is an excellent indicator of the amount of photosynthesis, or gross productivity, of plants in a given region.

Research in 2013, led by Joanna Joiner of NASA’s Goddard Space Flight Center in Greenbelt, Md., demonstrated that fluorescence from plants could be teased out from existing data from satellites that were designed and built for other purposes. The new research, led by Luis Guanter of the Freie Universität Berlin, used the data for the first time to estimate photosynthesis from agriculture. Results were published March 25 in the Proceedings of the National Academy of Sciences.

According to co-author Christian Frankenberg of NASA’s Jet Propulsion Laboratory in Pasadena, Calif., “The paper shows that fluorescence is a much better proxy for agricultural productivity than anything we’ve had before. This can go a long way regarding monitoring—and maybe even predicting—regional crop yields.”

Guanter, Joiner and Frankenberg launched their collaboration at a 2012 workshop, hosted by the Keck Institute for Space Studies at the California Institute of Technology (Caltech) in Pasadena, to explore measurements of photosynthesis from space. The team noticed that on an annual basis, the tropics are the most active in photosynthesis. But during the Northern Hemisphere’s growing season, the U.S. Corn Belt “really stands out,” Frankenberg said. “Areas all over the world are not as productive as this area.”

You are allowed to be impressed. It really is cool, after all.
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Jet Propulsion Laboratory. “Satellite Shows High Productivity from U.S. Corn Belt”. March 31, 2014.

(Tip o’the hat to S.L.)

Nothing to See Here, Just NASA Doing What it Does

Yes, that NASA:

NASA’s Lunar Laser Communication Demonstration (LLCD) has made history using a pulsed laser beam to transmit data over the 239,000 miles between the moon and Earth at a record-breaking download rate of 622 megabits per second (Mbps).

LLCD is NASA’s first system for two-way communication using a laser instead of radio waves. It also has demonstrated an error-free data upload rate of 20 Mbps transmitted from the primary ground station in New Mexico to the spacecraft currently orbiting the moon.

“LLCD is the first step on our roadmap toward building the next generation of space communication capability,” said Badri Younes, NASA’s deputy associate administrator for space communications and navigation (SCaN) in Washington. “We are encouraged by the results of the demonstration to this point, and we are confident we are on the right path to introduce this new capability into operational service soon.”

Since NASA first ventured into space, it has relied on radio frequency (RF) communication. However, RF is reaching its limit as demand for more data capacity continues to increase. The development and deployment of laser communications will enable NASA to extend communication capabilities such as increased image resolution and 3-D video transmission from deep space.

“The goal of LLCD is to validate and build confidence in this technology so that future missions will consider using it,” said Don Cornwell, LLCD manager at NASA’s Goddard Space Flight Center in Greenbelt, Md. “This unique ability developed by the Massachusetts Institute of Technology’s Lincoln Laboratory has incredible application possibilities.”

LLCD is a short-duration experiment and the precursor to NASA’s long-duration demonstration, the Laser Communications Relay Demonstration (LCRD). LCRD is a part of the agency’s Technology Demonstration Missions Program, which is working to develop crosscutting technology capable of operating in the rigors of space. It is scheduled to launch in 2017.

Heh. And here you thought the cool part of LADEE was the launch.

Reminder: When juxtaposing the insanely cool stuff NASA pulls off as a matter of routine in the course of being a public agency that regularly does its job just fine against the proposition of showing up to work in the morning and not making a special effort to completely botch the job, the notion arises that perhaps we should put the agency eggheads on the task of building a Congress that actually functions properly.

I mean, you know ….

They will get to that, I’m certain, right after they achieve faster-than-light travel while accidentally proving that God is a Buddhist hedgehog running a pâtisserie in Ballard.

In exchange for which … well, right. Congress will just … er … cut their budget.

Because, you know.

Will the Universe Give Up Its Dark Secrets?

“We’ve waited 18 years to write this paper, and we’re now making the final check.“

—Sam Ting

It’s always fun getting our hopes up. One might do well to wonder what is the anthropological value of ritual anticlimax. Or, as Jonathan Amos explains for BBC:

The scientist leading one of the most expensive experiments ever put into space says the project is ready to come forward with its first results.

The Alpha Magnetic Spectrometer (AMS) was put on the International Space Station to survey the skies for high-energy particles, or cosmic rays.

Nobel Laureate Sam Ting said the scholarly paper to be published in a few weeks would concern dark matter.