Tag: astronomy

Scientists finally image SMART-1 lunar impact site

11:00 am

SMART-1 impact site

Eleven years after the European SMART-1 probe was sent crashing onto the Moon’s surface, scientists have finally identified in a Lunar Reconnaissance Orbiter image that crash site.

The image is shown on the right, reduced and cropped to post here.

The images show a linear gouge in the surface, about four metres wide and 20 metres long, cutting across a small pre-existing crater. At the far end, a faint fan of ejecta sprays out to the south. Foing said: “The high resolution LRO images show white ejecta, about seven metres across, from the first contact. A north-south channel has then been carved out by the SMART-1 spacecraft body, before its bouncing ricochet. We can make out three faint but distinct ejecta streams from the impact, about 40 metres long and separated by 20-degree angles.”

Stooke said: “Orbit tracking and the impact flash gave a good estimate of the impact location, and very close to that point was a very unusual small feature. It now seems that impacts of orbiting spacecraft, seen here from SMART-1, and also in the cases from GRAIL and LADEE, will form elongated craters, most of whose rather faint ejecta extends downrange”.

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Post-hurricane update from Arecibo radio telescope

4:55 pm

USRA, the university consortium that operates the Arecibo radio telescope in Puerto Rico, has released an update on the observatory’s condition following Hurricane Maria.

Currently, we have no contact with the Observatory. One observatory staff member located in Arecibo Town contacted via short-wave radio reports that trees are down, power is out, houses damaged and roads impassable. We have no reason to believe that staff sheltered at Arecibo Observatory are in immediate danger since they have generators, well water and plenty of food. This is a rapidly changing situation, and we are trying to do the best we can to contact USRA employees and find out their status.

Essentially, they don’t know much at this point.

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More hearings stalling TMT

5:31 pm

Stall, stall: After spending 44 days of hearings before a retired judge, Hawaii is now forcing the consortium that wants to build the Thirty Meter Telescope on Mauna Kea to undergo further hearings before the local land board.

Wednesday’s hearing in a Hilo hotel comes after the retired judge overseeing contested-case hearings for the Thirty Meter Telescope recommended granting the project a construction permit. Riki May Amano issued her recommendation in July after hearing testimony that spanned 44 days. Opponents and supporters are echoing much of the arguments made during those oftentimes emotional days of testimony.

This short article, which really says little, ends by noting that “it’s not clear when the board will make a decision.”

Well, it is clear to me that the authorities in Hawaii, run exclusively by today’s racially-focused Democratic Party, is stalling as much as they can in order to force TMT to go elsewhere. They know it will not be a popular decision to block the telescope, but they also don’t want it because the hustlers of race on the island are against it. And to the Democratic Party today, the only thing that matters is to appease these race hustlers. So, they stall, figuring they can get rid of the telescope that way without ever having to block it outright.

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Hubble finds binary asteroid that also acts like a comet

10:54 am

Worlds without end: Astronomers using the Hubble Space Telescope have identified a strange new object in the asteroid belt, two asteroids closely orbiting each other while also acting like a comet.

The images of 288P, which is located in the asteroid belt between Mars and Jupiter, revealed that it was actually not a single object, but two asteroids of almost the same mass and size, orbiting each other at a distance of about 100 kilometres. That discovery was in itself an important find; because they orbit each other, the masses of the objects in such systems can be measured.

But the observations also revealed ongoing activity in the binary system. “We detected strong indications of the sublimation of water ice due to the increased solar heating — similar to how the tail of a comet is created,” explains Jessica Agarwal (Max Planck Institute for Solar System Research, Germany), the team leader and main author of the research paper. This makes 288P the first known binary asteroid that is also classified as a main-belt comet.

The data also suggests that this binary has only existed as such for a few thousand years, and probably broke into two pieces because of its rotation. When this happened, it exposed water ice buried below the surface, which having been exposed to sunlight is sublimating away and producing the binary’s cometlike of a tail and coma.

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New theory for formation of main asteroid belt

11:56 am

The uncertainty of science: Using computer models, astronomers have developed a new completely different theory to explain the existence of the asteroid belt between Mars and Jupiter.

The asteroid belt (sometimes referred to as the main asteroid belt) orbits between Mars and Jupiter. It consists of asteroids and minor planets forming a disk around the sun. It also serves as a sort of dividing line between the inner rocky planets and outer gas giants. Current theory suggests that the asteroid belt was once much more heavily populated, but the gravitational pull of Jupiter flung approximately 99 percent of its former material to other parts of the solar system or beyond. Astronomers also assumed that Jupiter’s gravity prevented the material in the belt from coalescing into larger planets. In this new effort, the researchers propose a completely different explanation of the asteroid belt’s origin—suggesting that the belt started out as an empty space and was subsequently filled by material flung from the inner and outer planets.

The new theory is interesting in that it really illustrates how little we really know about the formation of our solar system. The simple fact is that either one of these theories might be the answer, even though they propose completely opposite initial conditions. We simply do not have enough information about solar system formation in general to constrain our models and determine which of these theories is right.

Until scientists have been able to study hundreds, if not thousands, of solar systems up close, these models will be nothing more than interesting exercises in computer modeling.

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Hubble spots a pitch-black exoplanet

9:44 am

Astronomers using the Hubble Space Telescope have determined that an exoplanet is practically pitch black, reflecting almost no light.

NASA’s Hubble Space Telescope has observed a planet outside our solar system that looks as black as fresh asphalt because it eats light rather than reflecting it back into space. This light-eating prowess is due to the planet’s unique capability to trap at least 94 percent of the visible starlight falling into its atmosphere.

The oddball exoplanet, called WASP-12b, is one of a class of so-called “hot Jupiters,” gigantic, gaseous planets that orbit very close to their host star and are heated to extreme temperatures. The planet’s atmosphere is so hot that most molecules are unable to survive on the blistering day side of the planet, where the temperature is 4,600 degrees Fahrenheit. Therefore, clouds probably cannot form to reflect light back into space. Instead, incoming light penetrates deep into the planet’s atmosphere where it is absorbed by hydrogen atoms and converted to heat energy.

Because the exoplanet is tidally locked, with one side always facing its sun and the other always in nightime, the nighttime face is estimated to be about 2,000 degrees cooler, and actually shows evidence of the existence of water vapor and clouds.

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Astronomers search for water on Trappist-1 ecoplanets

10:54 am

The uncertainty of science: New research suggests that the Earth-sized exoplanets circling Trappist-1 might have water, or might not.

The data suggests the inner planets likely have lost all their water, but the outer planets, some of which are in the habitable zone, could have water. The key word is “could.” They actually don’t yet have any data that says for sure whether water is there..

Posted as we drive through Kayenta in the Navaho Reservation.

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Astronomers produce best image yet of a star

2:11 pm

The uncertainty of science: Astronomers have produced the best image so far of the surface face of a star.

The star is Antares, and it provides some details of the star’s complex outer layers. If I was home and had good internet access, I’d post it here.

At the same time, it should be noted that this is not a real image. It is recreated from four telescopes, using interferometry to combine the images, and also includes it a great deal of assumptions and uncertainties in its creation.

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To protect students from eclipse some schools will close Monday, or will keep their students indoors

9:54 am

The coming dark age: Fearful of the thunder gods, some school administrators have decided to close their schools or to keep their students indoors so they can’t see the eclipse on Monday.

CBS Miami reports some local schools in South Florida are giving kids an excused absence or even the day off to enjoy the eclipse, while others have decided to keep students inside for their safety.

The Scottsdale Unified School District in Arizona decided it was just too dangerous to let kids view the eclipse, especially after some reports of fake eclipse glasses on the market that might put eyes at risk, CBS Phoenix affiliate KPHO reports. “So without us being able to control the equipment that’s being used, if it’s donated or something, and also when you’re talking about a large amount of children it’s also very difficult to convince all of the kids to not look up. That’s not to say our kids won’t be very well behaved but if there’s even a question that there could be something unsafe, Scottsdale’s not going to take the chance,” said Erin Helm with Scottsdale Unified.

The quote is from the second link above. The first link describes the decision of Ohio schools to close.

It is horrifying that there are school officials out there who would actually act to prevent children from experiencing the eclipse out of fear. Kids are smart enough to know not to look at the Sun, if you tell them not to. And it is the responsibility of the school to provide them the right kinds of eclipse glasses, which do not cost a lot and can easily be purchased.

In fact, it is revealing that the schools doing this are all public schools, and thus provides more evidence that the public schools might be the worst place to send kids to get educated.

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“One of the greatest discoveries of the century is based on these things and we don’t even know what they are, really.”

9:42 am

The uncertainty of science: New research suggests that astronomers have little understanding of the supernovae that they use to estimate the distance to most galaxies, estimates they then used to discover dark energy as well as measure the universe’s expansion rate.

The exploding stars known as type Ia supernovae are so consistently bright that astronomers refer to them as standard candles — beacons that are used to measure vast cosmological distances. But these cosmic mileposts may not be so uniform. A new study finds evidence that the supernovae can arise by two different processes, adding to lingering suspicions that standard candles aren’t so standard after all.

The findings, which have been posted on the arXiv preprint server and accepted for publication in the Astrophysical Journal, could help astronomers to calibrate measurements of the Universe’s expansion. Tracking type Ia supernovae showed that the Universe is expanding at an ever-increasing rate, and helped to prove the existence of dark energy — advances that secured the 2011 Nobel Prize in Physics.

The fact that scientists don’t fully understand these cosmological tools is embarrassing, says the latest study’s lead author, Griffin Hosseinzadeh, an astronomer at the University of California, Santa Barbara. “One of the greatest discoveries of the century is based on these things and we don’t even know what they are, really.”

The key to understanding this situation is to maintain a healthy skepticism about any cosmological theory or discovery, no matter how enthusiastically touted by the press and astronomers. The good astronomers do not push these theories with great enthusiasm as they know the feet of clay on which they stand. The bad ones try to use the ignorant mainstream press to garner attention, and thus funding.

For the past two decades the good astronomers have been diligently checking and rechecking the data and the supernovae used to discover dark energy. Up to now this checking seems to still suggest the universe’s expansion is accelerating on large scales. At the same time, our knowledge of supernovae remains sketchy, and thus no one should assume we understand the universe’s expansion rate with any confidence.

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Ten planetary probes track a solar eruption through the solar system

9:02 am

The path of an October 2014 solar eruption was tracked by ten different spacecraft, including Curiosity on the surface of Mars, as its blast moved outward through the solar system.

The measurements give an indication of the speed and direction of travel of the CME [Coronal Mass Ejection], which spread out over an angle of at least 116 degrees to reach Venus Express and STEREO-A on the eastern flank, and the spacecraft at Mars and Comet 67P Churyumov–Gerasimenko on the western flank.

From an initial maximum of about 1000 kilometers per second (621 miles per second) estimated at the sun, a strong drop to 647 kilometers per second (402 miles per second) was measured by Mars Express three days later, falling further to 550 kilometers per second (342 miles per second) at Rosetta after five days. This was followed by a more gradual decrease to 450–500 kilometers per second (280-311 miles per second) at the distance of Saturn a month since the event.

The CME was first detected by solar observatories Proba-2, SOHO, Solar Dynamics Observatory, and STEREO-A.It was then tracked as it moved outward by Venus Express, Mars Express, MAVEN, Mars Odyssey, Curiosity, Rosetta, Cassini, and even New Horizons and Voyager 2.

On my last appearance on Coast to Coast, I was specifically asked if the probes to Venus, Mars, and other planets have the capability to track solar events. I knew that the Voyager spacecraft had equipment to do this, but was unsure about other planetary probes. This article answers that question.

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Amazon refunding customers who bought fake eclipse glasses

9:43 am

Amazon is issuing refunds to any customers who bought fake eclipse glasses through the site.

It is essential for people who are going to view the eclipse to understand that as long as the Sun is even partially visible, even by a sliver, it can cause significant eye damage if viewed without proper protection. Make sure your eclipse glasses or filters are safe! And remember, only during the short 2 minute or so totality that will occur in the narrow strip across the country will it be safe to look at the Sun without protection. Even so, you must do so with great caution so that you don’t mistakenly view the Sun unprotected when it is partially exposed.

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