Tag: science

Comet 67P/C-G’s coma fluctuates widely

12:57 pm

Climate change: Data from Rosetta has shown that the coma surrounding Comet 67P/C-G’s nucleus varies far more than had been expected by Earth-based observations.

“From a telescope, images of a comet’s atmosphere suggest that the coma is uniform and does not vary over short periods of hours or days. That’s what we were expecting as we approached the comet,” said Dr. Stephen Fuselier, a director in the SwRI Space Science and Engineering Division and the lead U.S. co-investigator for the Rosetta Orbiter Spectrometer for Ion and Neutral Analysis Double Focusing Mass Spectrometer (ROSINA DFMS) instrument. “It was certainly a surprise when we saw time variations from 200 km away. More surprising was that the composition of the coma was also varying by very large amounts. We’re taught that comets are made mostly of water ice. For this comet, the coma sometimes contains much more carbon dioxide than water vapor.”

The variations might be seasonal, or even reflect a variation from day to night.

Expect more news stories about Comet 67P/C-G from Rosetta. The journal Science is today publishing a special section on results from Rosetta.

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Comet 67P/C-G’s plumes

8:42 am

plumes from Comet 67P/C-G

The science team running Rosetta has released an image (cropped by me on the right) from the probe’s high resolution camera showing the fine structure of Comet 67P/C-G’s plumes.

I call them plumes rather than jets, which is the word the scientists use as well as everyone else, because it appears to me that they really aren’t jets, tightly confined flows of material coming from a nozzle-like opening. Instead, the image makes me think of very fast-rising plumes of smoke rising from an extinguished fire.

This image was taken in November, and is one of only a very tiny handful of images released from the high resolution camera. Rosetta’s science team has been very possessive of images from this camera, holding them back for their own research papers to follow in the future. Even here, the image is not very detailed. I wonder what cool stuff this camera has snapped close in that they have not yet shown us.

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New Horizons to begin observations of Pluto

4:23 pm

In preparing for its July 14 fly-by of Pluto, New Horizons will take its first images of the planet on January 25.

Snapped by New Horizons’ telescopic Long-Range Reconnaissance Imager, known as LORRI, those pictures will give mission scientists a continually improving look at the dynamics of those moons. And they’ll play a critical role in navigating the spacecraft as it covers the remaining 135 million miles (220 million kilometers) to Pluto. “We’ve completed the longest journey any craft has flown from Earth to reach its primary target, and we are ready to begin exploring!” said Alan Stern, New Horizons principal investigator from Southwest Research Institute in Boulder, Colorado.

Over the next few months, LORRI will take hundreds of pictures of Pluto against star fields to refine the team’s estimates of New Horizons’ distance to Pluto. Though the Pluto system will resemble little more than bright dots in the camera’s view until May, mission navigators will use those data to design course-correction maneuvers that aim the spacecraft toward its flyby target point this summer. The first such maneuver could occur as early as March.

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Scientists demand more skepticism of doom-sayers

9:04 am

The uncertainty of science: Ocean scientists have published a review of the literature, criticizing the ocean science field and the journals and journalists who report on it for overstating the environmental damage to the oceans.

The state of the world’s seas is often painted as verging on catastrophe. But although some challenges are very real, others have been vastly overstated, researchers claim in a review paper. The team writes that scientists, journals and the media have fallen into a mode of groupthink that can damage the credibility of the ocean sciences. The controversial study exposes fault lines in the marine-science community.

Carlos Duarte, a marine biologist at the University of Western Australia in Perth, and his colleagues say that gloomy media reports about ocean issues such as invasive species and coral die-offs are not always based on actual observations. It is not just journalists who are to blame, they maintain: the marine research community “may not have remained sufficiently sceptical” on the topic. [emphasis mine]

Gee, what a concept! These guys actually want scientists to base their claims of environmental disaster on actual observations. Who wodda thunk it?

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A 132-year-old Winchester rifle found leaning on a tree in national park

11:06 pm

Archeologists made the astonishing discovery of a 132 year old Winchester rifle leaning against a tree in Great Basin National Park in Nevada during a survey sweep.

“The 132 year-old rifle, exposed to sun, wind, snow, and rain was found leaning against a tree in the park. The cracked wood stock, weathered to grey, and the brown rusted barrel blended into the colors of the old juniper tree in a remote rocky outcrop, keeping the rifle hidden for many years,” Great Basin National Park said in a statement.

They hope with some historical research they might be able to identify who left the rifle there more than a century ago.

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Cats vs dogs in genome research

10:01 am

After an initial focus on studying the genomes of dogs, genetics researchers are now switching to cats.

After the completion of the human, mouse and rat genomes, the US National Institutes of Health organized a commission to decide on their next target; the dog genome was selected for high-quality sequencing, whereas cats were put on hold.

That got some cat geneticists’ backs up. “The truth is there were more powerful people interested in dogs,” says Stephen O’Brien, director of the Theodosius Dobzhansky Center for Genome Bioinformatics in St Petersburg, Russia, who led the initial cat-sequencing efforts.

There is now a project which, for only $7,500, allows scientists to map the genome of any cat for the cause of science. Under this program, they’ve already done 56 cats, including a kitten and her parents.

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Travel posters for alien worlds

8:46 am

NASA has produced retro-style travel posters for three alien exoplanets which you can download and print.

The posters are quite cool, which is not surprising, considering that, in the past four decades, the best interplanetary travel that NASA has been able to achieve has been its graphic power-point and pr images. Unfortunately, for NASA actually going there has not been so easy.

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Ancient fossils on Mars?

8:41 am

A close look at features on the Martian surface seen by Curiosity suggests to one scientist the presence of ancient fossils of carpet-like microbiology.

On Earth, carpet-like colonies of microbes trap and rearrange sediments in shallow bodies of water such as lakes and costal areas, forming distinctive features that fossilize over time. These structures, known as microbially-induced sedimentary structures (or MISS), are found in shallow water settings all over the world and in ancient rocks spanning Earth’s history.

Nora Noffke, a geobiologist at Old Dominion University in Virginia, has spent the past 20 years studying these microbial structures. Last year, she reported the discovery of MISS that are 3.48 billion years old in the Western Australia’s Dresser Formation, making them potentially the oldest signs of life on Earth.

In a paper published online last month in the journal Astrobiology (the print version comes out this week), Noffke details the striking morphological similarities between Martian sedimentary structures in the Gillespie Lake outcrop (which is at most 3.7 billion years old) and microbial structures on Earth.

Noffke is very careful in her analysis. She doesn’t claim any proofs, only that her expert eye sees the same things on both planets. Most intriguing.

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The sunspot cycle update for December

3:49 pm

The monthly update by NOAA of the solar cycle, showing the sunspot activity for the Sun in December, was released this past weekend. As I do every month, I am posting it here, below the fold, with annotations to give it context.

Even though sunspot activity in December increased, the slow ramp down to solar minimum continues to track the 2009 prediction of the solar scientist community. The overall intensity of the solar maximum prior to 2014 was considerable less than this prediction, but the numbers throughout 2014 matched that prediction remarkably well.
» Read more

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Comet impact theory replaced by common house fires

8:56 am

The uncertainty of science: Fused droplets found in many places across the globe and theorized to have come from a comet major impact that caused a major climate change around 13,000 years ago have now been found to have instead come from common house fires.

Since the 1970s when the Walter Alvarez found evidence of an asteroid impact in the Yucatan that could have caused the dinosaur extinction 65 million years ago, planetary scientists have seen asteroid or comet impacts everywhere. After all, impacts are cool disasters that play well to television producers and funding agencies.

Read this story however. It describes some very solid scientific work that wipes out one one of those cool theories, replacing it with something quite mundane.

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New Hubble images to celebrate its upcoming 25th anniversary

8:46 am

The Space Telescope Science Institute (STScI) that operates the Hubble Space Telescope yesterday released two spectacular new images at the January meeting of the American Astronomical Society.

They also announced new data from Hubble that suggests a major eruption had occurred at the center of the Milky Way about two million years ago.

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More Earthlike exoplanets confirmed

8:28 am

Worlds without end: Astronomers have confirmed from Kepler data the existence of 8 new exoplanets, all capable of having liquid water on their surface, with two more like Earth than any previous discovery.

These findings nearly double the number of known planets in the habitable zone, but researchers are especially excited about two of the new exoplanets: Their size, location, and star type means they could be rocky planets like Earth — which means they could have evolved life as we recognize it.

One of the planets, Kepler-438b, is only 12 percent bigger than Earth in diameter. That means it’s quite likely a rocky planet. Scientists have given it a 70 percent chance. Kepler-442b is a bit bigger at around 33 percent larger than Earth, but still has a 60 percent chance of being rocky.

But while 438b hits the sweet spot in size, 442b has it beat when it comes to distance from the sun. Both planets orbit a small red dwarf star, cooler than Earth’s Sun, but they also orbit more closely. 438b gets 40 percent more light than Earth, which means it has around a 70 percent chance of being able to hold liquid water. But with 66 percent as much light as our own planet, 442b has a 97 percent chance of being in the habitable zone.

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Why the pause in global temperature rise?

10:48 pm

The pause in global temperature rise has now lengthened past 18 years, and climate scientist Fred Singer asks some good scientific questions why.

Global warming skeptics like myself have been quick to note the long pause in any temperature increase since 1998, the lack of which has essentially invalidated all the climate models put forth by the global warming activists in the climate community. Singer goes one step further, however, asking the next question: Why has the temperature not risen? He doesn’t know, but he does put forth a number of suspects that the good scientists in the climate field should be pursuing, assuming they can open their eyes and work with real data for a change.

As usual, it isn’t as simple as we would like. The sun for example might explain it, but so could a lot of other factors, including a number put forth by global warming advocates. Good science demands that we look at them all, and find out the truth, rather than cherry-pick our favorite answer and ignore all other evidence.

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