The Saga Continues: Are Brown Dwarfs Stars, Planets or Neither?

By Amber Jorgenson | September 18, 2018 2:55 pm
An artist's illustration shows the Epsilon Indi system, with two brown dwarfs at the forefront and a main sequence star off in the distance. (Credit: Roberto Molar Candanosa and Sergio Dieterich, courtesy of the Carnegie Institution for Science)

An artist’s illustration shows the Epsilon Indi system, with two brown dwarfs at the forefront and a main sequence star off in the distance. (Credit: Roberto Molar Candanosa and Sergio Dieterich, courtesy of the Carnegie Institution for Science)

The universe is filled with billions of massive celestials objects, from stars to planets to comets to asteroids. But what happens when lines start to blur between these classifications, and we just can’t place an object in any major category?

Well, brown dwarfs know this better than anyone. They’re far too massive to be planets, but not massive enough for hydrogen atoms to fuse in their cores and become stars. They’ve straddled the line between planet and star since they were first confirmed in 1995, and it looks like they’re not getting out of limbo anytime soon.

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CATEGORIZED UNDER: Space & Physics
MORE ABOUT: exoplanets, stars

Scientists Discover Major Cause Of Inflammatory Bowel Disease

By Roni Dengler | September 18, 2018 2:30 pm
IBS stomach pain how it works IBD

Irritable bowel Disease is a painful syndrome that affects the intestines. Scientists say they’ve discovered a major driver of the disease. (Credit: RomarioIen/shutterstock)

Researchers have identified a prime culprit behind inflammatory bowel disease, or IBD, an incurable disorder that causes abdominal pain, diarrhea and weight loss from malnutrition. The discovery also reveals a pathway to treatment, scientists report today in the journal Cell Reports.

“We were able to block the inflammation, basically block IBD,” said Ze’ev Ronai, a biologist at Sanford Burnham Prebys Medical Discovery Institute in La Jolla, California, who led the new research.
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CATEGORIZED UNDER: Health & Medicine
MORE ABOUT: personal health

Kilopower Project: Los Alamos’ New Nuclear Reactors Could Power Spacecraft and Moon Bases

By John Wenz | September 17, 2018 6:00 pm
Kilopower nuclear reactor is tested on the moon it could power space colony or base

The Kilopower small nuclear reactor could be tested on the moon in the coming years. (Credit: NASA)

The future of space exploration may rest in the hands of a group of Los Alamos National Laboratory researchers. They’ve built the first of a new generation of small nuclear reactors intended to power missions to deep space and even future astronaut bases on the moon and Mars.

Called Kilopower, their project aims to achieve a longstanding dream of the space community: a safe, effective, and powerful nuclear power reactor that can power spacecraft for years.

“I don’t think we can expand into deep space without nuclear power, which is what’s made me so passionate about developing the technology,” says David Poston, who leads the Kilopower team.
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CATEGORIZED UNDER: Space & Physics, top posts

Activity – Not Rest – Speeds Recovery After Brain Injury in Mice

By Roni Dengler | September 17, 2018 5:00 pm
a white mouse in a cage

Scientists gave mice brain injuries (this particular mouse was not involved) and then watched how fast they recovered. They found that active mice recovered faster than ones given rest. (Credit: Kirill Kurashov/shutterstock)

Conventional wisdom advocates for rest after suffering an injury. Now researchers have discovered that activity — not rest — helps the brain recover from trauma in mice. The finding suggests that challenging the brain early after damage can speed up healing.

“Lengthy rest periods are supposed to be key to the brain’s healthy recovery, but our study in mice demonstrates that re-engaging the brain immediately after injury can actually be more helpful than resting it,” study lead Randy Bruno, a neuroscientist at Columbia University’s Zuckerman Institute in New York City, said in a statement.

The results were “completely unexpected,” he added.
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CATEGORIZED UNDER: Mind & Brain, top posts

The Milky Way’s Stars Travel Far and Wide from their Birthplaces

By Amber Jorgenson | September 17, 2018 4:48 pm
The Milky Way. (Credit: Serge Brunier)

The Milky Way Galaxy. (Credit: Serge Brunier)

Mapping our galaxy’s formation and evolution would be pretty easy if stars just stayed in their birthplaces, but unfortunately that’s not the case. The Milky Way’s vast pool of stars is constantly expanding outward, getting knocked out of their orbits, and generally evolving alongside our galaxy. Sure, this makes for an exciting stellar journey, but these gradual movements make it difficult to pinpoint a star’s origins and track our galactic history.

However, a team of researchers has found a way to peer into a star’s past and identify where in the galaxy it was born. By figuring out the ages and chemical abundances of our stellar population, researchers would be able to piece together the Milky Way’s past and possibly predict its future.

Stellar Shuffle

A star’s movement throughout its lifetime, known as radial migration, depends on a lot of different factors. In a spiral galaxy like our own, it’s thought that stars are pushed outward when they interact with the strong gravitational forces of the arms and galactic bar, and can be completely knocked out of orbit when smaller galaxies invade our borders.

But luckily, we’ve found a way to sort through this stellar turbulence. Due to the different elements strewn about our galaxy, a star born in a certain place at a certain time will have a chemical makeup that reflects the environment it formed in. So if we’re able to get a good look at a star and measure the relative abundances of materials within, we can trace it back to its birthplace and track its migration.

To get an in-depth look at a sample of stars, the research team borrowed data from ESO’s 3.6 m telescope at Chile’s La Silla Observatory. They analyzed roughly 600 stars that had been probed with HARP, the telescope’s high-powered spectrograph, and were able to estimate the stars’ ages and abundances of iron — an element leftover from supernovas that’s absorbed during star formation.

Their findings, published in the Monthly Notices of the Royal Astronomical Society, showed that the stars, all of which sit close to the Sun today, were born far and wide across the galactic disc — traveling significant distances from their homelands.

The left side of the images shows the condensed location of the sample of stars. The right side shows where in the galaxy the stars were born, having traveled significant distances during their lifetimes. Credit: I. Minchev (AIP)

The left side of the images shows the condensed location of the sample of stars. The right side shows where in the galaxy the stars were born. (Credit: I. Minchev (AIP))

Their simulations show that older stars in the sample were born closer to the galaxy’s center, and that younger stars were born further out in the disc — lining up with the theory that star formation gradually extends outward as a galaxy ages. Based on their estimates, our Sun itself has taken quite the galactic road trip, receding about 2,000 light-years during its 4.6 billion year lifetime.

“In the near future, applying this method to the extremely high-quality data from the Gaia mission and ground-based spectroscopic surveys will allow much more exact measurements of the migration history and, thus, the Milky Way past,” said the study’s co-author, Friedrich Anders of the Leibniz Institute for Astrophysics Potsdam, in a press release.

And by tracking how our stellar population has evolved so far, we could also get a good idea of where we’re heading, and what our galaxy might look like in another 13.5 billion years.

CATEGORIZED UNDER: Space & Physics
MORE ABOUT: stars

Volcanoes of Mud Erupt From Giant Asteroid Ceres

By John Wenz | September 17, 2018 10:00 am
(Credit: NASA/JPL-Caltech/UCLA/MPS/DLR/IDA)

(Credit: NASA/JPL-Caltech/UCLA/MPS/DLR/IDA)

Nothing is normal on Ceres — least of all its mud volcanoes.

In new research published in Nature Astronomy, a large team of astronomers has laid out a new view of the weirdest world in our solar system. It seems that Ceres has had a busy last few billion years — including random smatterings of volcanism, but of a type seen nowhere else in the solar system.

Ceres is the largest world in the asteroid belt, and is believed to be a remnant proto-planet, or the kind of small worlds that served as the building blocks of the planets we see today. There’s abundant evidence that Ceres may have once had an ocean that’s since frozen over, and the tantalizing clues to a geologically active history.

Ceres even appears to have a form of volcanism. There are two types of volcanism in the solar system, typically: the kinds of magma eruptions seen on Earth and Jupiter’s moon Io, where heated rock wells up from the core to the surface. And then there’s the kind of volcanism seen on Europa and Enceladus, where large plumes of frozen water erupt. Scientists call this cryovolcanism.
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CATEGORIZED UNDER: Space & Physics, top posts

NASA Launches $1 Billion ICESat-2 Spacecraft to Study Ice Melt

By Katherine Mast | September 15, 2018 10:30 am
ICESat-2 satellite spacecraft orbits Earth

NASA’s ICESat-2 spacecraft will measure the height of Earth’s melting ice. (Credit: NASA Goddard Space Flight Center)

Since 2003, NASA has been monitoring the height of Earth’s ice with lasers. This undertaking began with a satellite — the Ice, Cloud, and Land Elevation Satellite (ICESat) — which ran through 2009. Operation IceBridge has used planes to monitor specific vulnerable ice sheets in the years since. Now, the project continues with ICESat-2, which successfully launched September 15 from Vandenberg Air Force Base in California.

Bearing one of the most sophisticated elevation-monitoring lasers ever made, ICESat-2 will measure the height of Earth’s ice, seas, land and trees for the next three-to-seven years, helping to produce a detailed, 3-D map of the planet and detect small, annual changes in elevation. If a glacier loses even 4 millimeters of height, ICESat-2 will let us know.
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CATEGORIZED UNDER: Environment, Space & Physics

New Planet-Hunting Space Telescope is Already Finding New Worlds

By Elizabeth Howell | September 14, 2018 6:30 pm
TESS NASA spacecraft hunts exoplanets

The Transiting Exoplanet Survey Satellite, or TESS, is designed to hunt for planets among nearby bright stars. (Credit: NASA’s Goddard Space Flight Center)

In just six weeks of science observations, NASA’s Transiting Exoplanet Survey Satellite (TESS) has already found 50 possible new worlds for scientists to examine.

TESS finds planets by watching the dip in light as a planet passes in front of its parent star. It began science observations on July 25 and the first set of information was available to astronomers on September 5, but the first step in examining TESS’ data is to eliminate false positives. Sometimes a possible “planet” will actually be a binary star blocking its companion’s light, or it could be sunspots on the star’s surface, no second body needed.

While most of these planetary candidates will be discarded upon future analysis, principal investigator George Ricker at the Massachusetts Institute of Technology told Astronomy there are likely six new bona-fide planets lurking in this data alone. Ricker says that usually five to 20 percent of planetary candidates turn out to be true planets, once the transit method is followed up by the radial velocity method on the ground (which observes the influence of an orbiting object). And even amateurs can help with the search, he said.

“We make alerts available to astronomers worldwide, and we continue to do that, because there are a lot of amateurs with superb instruments they can use for the initial parts of the screening,” Ricker said, adding the process will likely take months or years due to the number of planetary candidates – suspected rocky planets and larger ones – to double-check.

“As we become more adept at seeking these things out, we are going to get 100 or 200 more [candidates] per sector. There will be a lot to work through. I expect there are going to be 3,000 or so potential objects of interest,” he added.

light curve transiting exoplanet tess spacecraft nasa


The transit method of exoplanet detection involves staring at a single star to look for dips in its light associated with the passage of a planet. (Credit:
NASA)

Hunt for Nearby Planets

It’s a promising start for TESS, which is supposed to find 50 rocky planets — worlds that are four times Earth’s diameter, or smaller — in its primary three-year mission. NASA is on a long-term hunt for planets like Earth, and with the long-running Kepler planet-hunter mission running low on fuel, TESS is billed as a logical successor to Kepler’s work.

While Kepler’s primary mission focused on distant stars in a zone of the constellation Cygnus, TESS is an all-sky survey optimized to look at close-up stars. It travels in a never-before-used lunar-resonant orbit that brings TESS around Earth twice for every time that the Moon circles the Earth once. TESS moves its wide view between different sectors of the sky roughly every month.

TESS will study stars that are 30 to 100 times brighter than those surveyed by Kepler. Brighter stars are easier to observe from the ground if something interesting is found, they are also likely closer than most of Kepler’s stars. So the hope is with TESS observations, there will soon be a network of telescopes doing follow-up work on the planets it finds.

All NASA missions go through periodic reviews to determine if they should receive more funding for longer periods of work. So far, indications are positive that TESS will exceed its initial goal of 50 rocky planets; TESS’ observations are already cleaner (better signal to noise) than expected. The spacecraft is also expected to find planets that are larger and gaseous, but its formal goal is more focused on rocky planets.

Furthermore the spacecraft’s trajectory is so efficient that TESS has enough remaining fuel to do its observations for another century or two; in other words, unlike Kepler, the spacecraft’s end of life will not come from running out of gas. TESS has also effectively tripled its storage capacity because the spacecraft is more stable than expected in its orbit; this means it takes fewer bits per pixel to generate an image and store it on the spacecraft. (Bits per pixel is a measurement of how much information is stored in the image; more bits per pixel requires a larger file size.)

During the extended mission, Ricker said the team will try to send information down to Earth even more quickly to catch more short-term phenomena. TESS has already spied several new near-Earth asteroids, one comet, and a supernova during its short time in orbit, but adding a more rapid response will allow astronomers to see more star explosions — as well as events such as tidal disruptions in stars that are orbiting close to another object, such as another star.

What the Future Holds for TESS

While the search for “Earth 2.0” is still ongoing, Ricker said it’s possible there already are small planets sitting in the TESS dataset. “We’ve seen indications that there are several small planets that are in this initial set, and we’re just going through the process of looking at them and making sure that we really got the properties set and it isn’t a false positive,” he said.

The candidates TESS finds will also serve as prime targets for follow up with the James Webb Space Telescope (JWST), currently set to launch in 2021. These worlds, if they possess Earth-like life, would have chemical signatures in their atmosphere visible in the infrared — exactly the wavelength regime in which JWST will operate. TESS’ sectors are also perfectly poised in JWST’s “continuous viewing zone,” which is the area of sky it will be able to observe at any time of the year during its orbit.

As TESS observations continue, the planets will come pouring in. And as telescopes on the ground and in space follow up, our galactic neighborhood will grow.

CATEGORIZED UNDER: Space & Physics
MORE ABOUT: exoplanets

Is Time Running Out For NASA’s Mars Opportunity Rover?

By Alison Klesman | September 14, 2018 4:30 pm
mars opportunity rover view of mars

A computer-generated Opportunity explores Burns Cliff on Mars.
(Credit: NASA/JPL-Caltech/Cornell)

Since June 10, the 14-year-old Opportunity rover has been silent, presumably sleeping as thick dust clouds blocked the Sun from its solar cells. But now, that sky is clearing, and NASA is implementing a listening plan for the rover through January 2019.

Without power, the rover has likely experienced several faults. Among them, its mission clock may have stopped recording time accurately. To counteract this possibility, the rover’s mission team is both passively waiting for the rover to communicate at predetermined times and actively pinging it with commands to respond, just in case the rover isn’t sure when it should be sending signals back to Earth.
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CATEGORIZED UNDER: Space & Physics, top posts
MORE ABOUT: mars, space exploration

Where Have All The Turtles Gone?

By Roni Dengler | September 14, 2018 4:00 pm
Aldabra giant tortoise

An Aldabra giant tortoise. (Credit: Ivan Hlobej/shutterstock)

Turtles survived the massive extinction event that took out the dinosaurs more than 60 million years ago. But climate change, habitat loss and exploitation from the commercial pet industry have now decimated global turtle populations.

Of the 356 turtle species scientists know about today, more than half are endangered or have already gone extinct. As their numbers continue to decline, scientists say their loss will alter ecosystems around the world.
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CATEGORIZED UNDER: Living World, top posts
MORE ABOUT: animals
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