Posts about NASA

NASA’s Mars Curiosity Rover

Curiosity is the name of the new rover from NASA. It will be launched to continue the exploration of Mars so successfully done by Spirit and Opportunity (2 previous Mars rovers that did some amazing work and laster years longer than expected). The rover is NASA’s Mars Science Laboratory, a mobile robot for investigating Mars’ past or present ability to sustain microbial life.

photo of NASA's Mars Rover: Curiosity

Once on the surface, the rover will be able to roll over obstacles up to 75 centimeters (29 inches) high and travel up to 90 meters per hour. On average, the rover is expected to travel about 30 meters per hour, based on power levels, slippage, steepness of the terrain, visibility, and other variables.

The rover is about the size of a small SUV — 10 feet long (not including the arm), 9 feet wide and 7 feet tall. It weighs 900 kilograms (2,000 pounds)

The rover will carry a radioisotope power system that generates electricity from the heat of plutonium’s radioactive decay. This power source gives the mission an operating lifespan on Mars’ surface of a full martian year (687 Earth days) or more, while also providing significantly greater mobility and operational flexibility, enhanced science payload capability, and exploration of a much larger range of latitudes and altitudes than was possible on previous missions to Mars.

Related: Mars Rover Continues ExplorationMars Rovers Getting Ready for Another Adventure (2007)Sunset on Mars

5% of the Universe is Normal Matter, What About the Other 95%?

Dark Matters from PHD Comics on Vimeo.

Great discussion and illustration of the state of our understanding of physics, matter, dark matter and the rest of the stuff our universe has from PhD comics. What is the universe made of? 5% of it is normal matter (the stardust we are made of), 20% dark matter and the other 75% – we have no idea!

Dark Cosmos is a nice book on some of these ideas. It is 5 years old so missing some of the latest discoveries.

Related: Why do we Need Dark Energy to Explain the Observable Universe?The Mystery of Empty SpaceFriday Fun, CERN Version
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Image of Map Showing Concentration of Life in Oceans

Image showing regions of life in the oceans

This image shows the abundance of life in the sea, measured by the SeaWiFS instrument aboard the Seastar satellite. Dark blue represents warmer areas where there is little life due to lack of nutrients, and greens and reds represent cooler nutrient-rich areas.

The nutrient-rich areas include coastal regions where cold water rises from the sea floor bringing nutrients along and areas at the mouths of rivers where the rivers have brought nutrients into the ocean from the land. NASA has posted a large gallery of great images for Earth Day.

Related: Altered Oceans: the Crisis at SeaMicrobes Beneath the Sea FloorA single Liter of Seawater Can Hold More Than One Billion Microorganisms

Evidence of Extraterrestrial Life Discovered?

Has evidence of extraterrestrial life been discovered? In Fossils of Cyanobacteria in CI1 Carbonaceous Meteorites , Richard B. Hoover, Ph.D. NASA/Marshall Space Flight Center, puts forth his evidence on the discovery of evidence of cyanobacteria in meteorites.

Dr. Hoover has discovered evidence of microfossils similar to Cyanobacteria, in freshly fractured slices of the interior surfaces of the Alais, Ivuna, and Orgueil CI1 carbonaceous meteorites. Based on Field Emission Scanning Electron Microscopy (FESEM) and other measures, Dr. Hoover has concluded they are indigenous to these meteors and are similar to trichomic cyanobacteria and other trichomic prokaryotes such as filamentous sulfur bacteria. He concludes these fossilized bacteria are not Earthly contaminants but are the fossilized remains of living organisms which lived in the parent bodies of these meteors, e.g. comets, moons, and other astral bodies. The implications are that life is everywhere, and that life on Earth may have come from other planets.

The importance of this claim is hard to ignore. The journal includes a statement from Dr. Rudy Schild, Center for Astrophysics, Harvard-Smithsonian, Editor-in-Chief, Journal of Cosmology:

Dr. Richard Hoover is a highly respected scientist and astrobiologist with a prestigious record of accomplishment at NASA. Given the controversial nature of his discovery, we have invited 100 experts and have issued a general invitation to over 5000 scientists from the scientific community to review the paper and to offer their critical analysis. Our intention is to publish the commentaries, both pro and con, alongside Dr. Hoover’s paper. In this way, the paper will have received a thorough vetting, and all points of view can be presented. No other paper in the history of science has undergone such a thorough analysis, and no other scientific journal in the history of science has made such a profoundly important paper available to the scientific community, for comment, before it is published. We believe the best way to advance science, is to promote debate and discussion.

Read the full paper.

The filaments have been observed to be embedded in freshly fractured internal surfaces of the stones. They exhibit features (e.g., the size and size ranges of the internal cells and their location and arrangement within sheaths) that are diagnostic of known genera and species of trichomic cyanobacteria and other trichomic prokaryotes such as the filamentous sulfur bacteria. ESEM and FESEM studies of living and fossil cyanobacteria show similar features in uniseriate and multiseriate, branched or unbranched, isodiametric or tapered, polarized or unpolarized filaments with trichomes encased within thin or thick external sheaths. Filaments found in the CI1 meteorites have also been detected that exhibit structures consistent with the specialized cells and structures used by cyanobacteria for reproduction (baeocytes, akinetes and hormogonia), nitrogen fixation (basal, intercalary or apical heterocysts) and attachment or motility (fimbriae).

These studies have led to the conclusion that the filaments found in the CI1 carbonaceous meteorites are indigenous fossils rather than modern terrestrial biological contaminants that entered the meteorites after arrival on Earth. The δ13C and D/H content of amino acids and other organics found in these stones are shown to be consistent with the interpretation that comets represent the parent bodies of the CI1 carbonaceous meteorites. The implications of the detection of fossils of cyanobacteria in the CI1 meteorites to the possibility of life on comets, Europa and Enceladus are discussed.

Has life been found in a meteorite? by Phil Plait
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Scientific Inquiry: Arsenic for Phosphorus in Bacteria Cells

As would be expected with significant new scientific claims, scientists are examining the evidence. On her blog, Rosie Redfield, who runs a microbiology research lab in the Life Sciences Centre at the University of British Columbia, disputes NASA’s recent claims. This is how science is suppose to work. Scientists provide evidence. Other scientists review the evidence, try to verify the claims with experiments of their own and the scientific inquiry process moves toward new knowledge.

Arsenic-associated bacteria (NASA’s claims)

NASA’s shameful analysis of the alleged bacteria in the Mars meteorite made me very suspicious of their microbiology, an attitude that’s only strengthened by my reading of this paper. Basically, it doesn’t present ANY convincing evidence that arsenic has been incorporated into DNA (or any other biological molecule).

The authors then grew some cells with radioactive arsenate (73-As) and no phosphate, washed and dissolved them, and used extraction with phenol and phenol:chloroform to separate the major macromolecules. The protein fraction at the interface between the organic and aqueous phases had about 10% of the arsenic label but, because the interface material is typically contaminated with liquid from the aqueous phase, this is not good evidence that the cells’ protein contained covalently-bound arsenate in place of phosphorus. About 75% of the arsenic label was in the ‘supernatant ‘fraction. The authors describe this fraction as DNA/RNA, but it also contains most of the small water-soluble molecules of the cell, so its high arsenic content is not evidence that the DNA and RNA contain arsenic in place of phosphorus. The authors use very indirect evidence to argue that the distribution of arsenic mirrors that expected for phosphate, but this argument depends on so many assumptions that it should be ignored.

I don’t know whether the authors are just bad scientists or whether they’re unscrupulously pushing NASA’s ‘There’s life in outer space!’ agenda. I hesitate to blame the reviewers, as their objections are likely to have been overruled by Science’s editors in their eagerness to score such a high-impact publication.

New claims have to provide strong evidence. time will tell if this discovery is actually a discovery. It will be amazing if it is, so I am pulling for it. But the story will need to have much more confirmation before we can be certain.

Arsenate-based DNA: a big idea with big holes

The study published in Science has a number of flaws. In particular, one subtle but critical piece of evidence has been overlooked, and it demonstrates that the DNA in question actually has a phosphate – not an arsenate -backbone.

Wolfe-Simon et al. used a technique called nanoSIMS to analyze elemental concentrations of the agarose gel at the location of the DNA band. They determined that the part of the gel containing DNA also contained both arsenic and phosphorus. But what did they really analyze?

The answer is that the nanoSIMS determined the concentration of arsenic in the gel – not specifically in the DNA.

Finally, there’s a simple experiment that could resolve this debate: analyze the nucleotides directly. Show a mass spectrum of DNA sequences demonstrating that nucleotides contain arsenate instead of phosphate. This is a very simple experiment, and would be quite convincing – but it has not been performed.

Related: It’s not an arsenic-based life formMono Lake bacteria build their DNA using arsenicClose Encounters of the Media Kind

Changing Life as We Know It

Update: Independent researchers find no evidence for arsenic life in Mono Lake

NASA has made a discovery that changes our understanding of the very makeup of life itself on earth. I think my favorite scientific discipline name is astrobiology. NASA pursues a great deal of this research not just out in space but also looking at earth based life. Their astrobiology research has changed the fundamental knowledge about what comprises all known life on Earth.

photo of Felisa Wolfe-Simon

Felisa Wolfe-Simon processing mud from Mono Lake to inoculate media to grow microbes on arsenic.

Carbon, hydrogen, nitrogen, oxygen, phosphorus and sulfur are the six basic building blocks of all known forms of life on Earth. Phosphorus is part of the chemical backbone of DNA and RNA, the structures that carry genetic instructions for life, and is considered an essential element for all living cells.

Phosphorus is a central component of the energy-carrying molecule in all cells (adenosine triphosphate) and also the phospholipids that form all cell membranes. Arsenic, which is chemically similar to phosphorus, is poisonous for most life on Earth. Arsenic disrupts metabolic pathways because chemically it behaves similarly to phosphate.

Researchers conducting tests in the harsh, but beautiful (see photo), environment of Mono Lake in California have discovered the first known microorganism on Earth able to thrive and reproduce using the toxic chemical arsenic. The microorganism substitutes arsenic for phosphorus in its cell components.

“The definition of life has just expanded,” said Ed Weiler, NASA’s associate administrator for the Science Mission Directorate. “As we pursue our efforts to seek signs of life in the solar system, we have to think more broadly, more diversely and consider life as we do not know it.” This finding of an alternative biochemistry makeup will alter biology textbooks and expand the scope of the search for life beyond Earth.

In science such huge breakthroughs are not just excepted without debate, however, which is wise.

Thriving on Arsenic:

In other words, every experiment Wolfe-Simon performed pointed to the same conclusion: GFAJ-1 can substitute arsenic for phosphorus in its DNA. “I really have no idea what another explanation would be,” Wolfe-Simon says.

But Steven Benner, a distinguished fellow at the Foundation for Applied Molecular Evolution in Gainesville, FL, remains skeptical. If you “replace all the phosphates by arsenates,” in the backbone of DNA, he says, “every bond in that chain is going to hydrolyze [react with water and fall apart] with a half-life on the order of minutes, say 10 minutes.” So “if there is an arsenate equivalent of DNA in that bug, it has to be seriously stabilized” by some as-yet-unknown mechanism.

It is sure a great story if it is true though. Other scientists will examine more data and confirm or disprove the claims.

“We know that some microbes can breathe arsenic, but what we’ve found is a microbe doing something new — building parts of itself out of arsenic,” said Felisa Wolfe-Simon, a NASA Astrobiology Research Fellow in residence at the U.S. Geological Survey in Menlo Park, Calif., and the research team’s lead scientist. “If something here on Earth can do something so unexpected, what else can life do that we haven’t seen yet?”
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NASA to Launch GM Co-Developed Robot to International Space Station

photo of humanoid GM NASA roblot

NASA will launch the first human-like robot to space later this year to become a permanent resident of the International Space Station. Robonaut 2, or R2, was developed jointly by NASA and General Motors under a cooperative agreement to develop a robotic assistant that can work alongside humans, whether they be astronauts in space or workers at GM manufacturing plants on Earth.

The 300-pound R2 consists of a head and a torso with two arms and two hands and will launch on space shuttle Discovery as part of the STS-133 mission planned for September. Once aboard the station, engineers will monitor how the robot operates in weightlessness. R2 joins another station robot, known as Dextre. That robot, built by the Canadian Space Agency, consists of two, long arms to perform tasks that normally require spacewalking astronauts to complete.

While Dextre is located on the station’s exterior, R2 will be confined to operations in the station’s Destiny laboratory. However, future enhancements could allow it to move more freely around the station’s interior, and it could one day be modified to operate outside the complex.

“The use of R2 on the space station is just the beginning of a quickening pace between human and robotic exploration of space,” said John Olson, director of NASA’s Exploration Systems Integration Office. “The partnership of humans and robots will be critical to opening up the solar system and will allow us to go farther and achieve more than we can probably even imagine today.”

The dexterous humanoid robot not only looks like a human, it is designed to work like one. With human-like hands and arms, R2 is able to use the same tools that station crew members use. In the future, the greatest benefit of humanoid robots in space may be as an assistant or stand-in for astronauts during spacewalks or for tasks too difficult or dangerous for humans. For now, R2 is still a prototype and lacks adequate protection needed to exist outside the space station in the extreme temperatures of space.

Related: Awesome Robot: uBot-5RoboCup German Open 2008Toyota Develops Thought-controlled WheelchairThe Robotic Dog

Surprise Shrimp Under Antarctic Ice

A three-inch long Lyssianasid amphipod found 600 feet beneath the Ross Ice Shelf stars in a recent popular webcast (see below). NASA scientists were using a borehole camera to look back up towards the ice surface when they spotted this pinkish-orange creature swimming beneath the ice.

Stacy Kim of Moss Landing Marine Laboratory was the first biologist to see the video and immediately recognized it as a Lyssianasid amphipod. It was about 3 inches long and Stacy concluded that this meant there was quite an extensive biological community under the ice here – even 20 miles from open water.

Related: Iron-breathing Species Isolated in Antarctic for Millions of YearsPine Island Glacier (PIG) Ice ShelfThe Brine Lake Beneath the SeaLake Under 2 Miles of Ice
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Friday Fun: Hammer and Feather Drop on Moon

Gravity acts in the same way on a feather and hammer. The reason the hammer falls faster on earth is due to air resistance (well and if you try outside – wind could blow the feather too).

At the end of the last Apollo 15 moon walk, Commander David Scott performed a live demonstration for the television cameras. He held out a geologic hammer and a feather and dropped them at the same time. Because they were essentially in a vacuum, there was no air resistance and the feather fell at the same rate as the hammer, as Galileo had concluded hundreds of years before – all objects released together fall at the same rate regardless of mass. Mission Controller Joe Allen described the demonstration in the “Apollo 15 Preliminary Science Report”:

During the final minutes of the third extravehicular activity, a short demonstration experiment was conducted. A heavy object (a 1.32-kg aluminum geological hammer) and a light object (a 0.03-kg falcon feather) were released simultaneously from approximately the same height (approximately 1.6 m) and were allowed to fall to the surface. Within the accuracy of the simultaneous release, the objects were observed to undergo the same acceleration and strike the lunar surface simultaneously, which was a result predicted by well-established theory, but a result nonetheless reassuring considering both the number of viewers that witnessed the experiment and the fact that the homeward journey was based critically on the validity of the particular theory being tested.

Related: posts on physicsPhun PhysicsLearning About the MoonWhat Are Flowers For?

Extremophile Hunter

NSF has begun publishing a new web magazine: Science Nation. The inaugural article is Extremophile Hunter

Astrobiologist Richard Hoover really goes to extremes to find living things that thrive where life would seem to be impossible–from the glaciers of the Alaskan Arctic to the ice sheets of Antarctica.

“It may be that when we ultimately get a chance to bring back samples of ice from the polar caps of Mars, we might find biology that looks just like Earth life and it might be that it originated on Earth and was carried to Mars,” said Hoover. “Of course, if it can happen that way, it could have happened the other way. So we may never know the ultimate answer to how did life originate.”

Some of the structures he has imaged from these meteorites are intriguing, bearing striking similarities to bacteria here on Earth. Could these be the fossilized remains of extraterrestial life?

“I am convinced that what I am finding in the carbonaceous meteorites are in many cases biological in nature, and I think they are indigenous and not terrestrial contaminants,” said Hoover.

It is a highly controversial interpretation. “We have for a long time thought that all life, as we know it, originated on Earth. And there isn’t any life anywhere else,” he said. “That’s an idea, it’s a hypothesis, it’s a totally unproven hypothesis.”

Related: TardigradesWhat is an Extremophile?Light-harvesting Bacterium Discovered in Yellowstone

Evolution, Methane, Jobs, Food and More

photo of sunset on Mars
Photo from May 2005 by NASA’s Mars Exploration Rover Spirit as the Sun sank below the rim of Gusev crater on Mars.

Science Friday is a great National Public Radio show. The week was a great show covering Antimicrobial Copper, Top Jobs for Math and Science, Human-Driven Evolution, Methane On Mars, Fish with Mercury and more. This show, in particular did a great job of showing the scientific inquiry process in action.

“Fishing regulations often prescribe the taking of larger fish, and the same often applies to hunting regulations,” said Chris Darimont, one of the authors of the study. “Hunters are instructed not to take smaller animals or those with smaller horns. This is counter to patterns of natural predation, and now we’re seeing the consequences of this management.” Darimont and colleagues found that human predation accelerated the rate of observable trait changes in a species by 300 percent above the pace observed within purely natural systems, and 50 percent above that of systems subject to other human influences, such as pollution

Very interesting stuff, listen for more details. A part of what happens is those individuals that chose to focus on reproducing early (instead of investing in growing larger, to reproduce later) are those that are favored (they gain advantage) by the conditions of human activity. I am amazed how quickly the scientists says the changes in populations are taking place.

And Methane On Mars is another potentially amazing discovery. While it is far from providing proof of live on Mars it is possibly evidence of life on Mars. Which would then be looked back on as one of the most important scientific discoveries ever. And in any even the podcast is a great overview of scientists in action.

This week astronomers reported finding an unexpected gas — methane — in the Martian atmosphere. On Earth, a major source of methane is biological activity. However, planetary scientists aren’t ready to say that life on Mars is to blame for the presence of the gas there, as geochemical processes could also account for the finding. The find is intriguing especially because the researchers say they have detected seasonal variations of methane emissions over specific locations on the planet.

Martian Methane Reveals the Red Planet is not a Dead Planet
The Mars Methane Mystery: Aliens At Last?

Related: Mars Rover Continues ExplorationCopper Doorknobs and Faucets Kill 95% of SuperbugsViruses and What is Lifeposts on evolutionScience and Engineering Link Directory

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