Tag: science

Gaia releases 3D map of galaxy

8:17 am

The science team for the space telescope Gaia, designed to map the positions of billions of stars, have released the probe’s second catalog, producing a 3D map of 1.7 billion stars in the Milky Way

The new data release, which covers the period between 25 July 2014 and 23 May 2016, pins down the positions of nearly 1.7 billion stars, and with a much greater precision. For some of the brightest stars in the survey, the level of precision equates to Earth-bound observers being able to spot a Euro coin lying on the surface of the Moon.

With these accurate measurements it is possible to separate the parallax of stars – an apparent shift on the sky caused by Earth’s yearly orbit around the Sun – from their true movements through the Galaxy. The new catalogue lists the parallax and velocity across the sky, or proper motion, for more than 1.3 billion stars. From the most accurate parallax measurements, about ten per cent of the total, astronomers can directly estimate distances to individual stars.

The catalog provides much more information than this. For example:

As well as positions, the data include brightness information of all surveyed stars and colour measurements of nearly all, plus information on how the brightness and colour of half a million variable stars change over time. It also contains the velocities along the line of sight of a subset of seven million stars, the surface temperatures of about a hundred million and the effect of interstellar dust on 87 million.

Gaia also observes objects in our Solar System: the second data release comprises the positions of more than 14 000 known asteroids, which allows precise determination of their orbits. A much larger asteroid sample will be compiled in Gaia’s future releases.

Further afield, Gaia closed in on the positions of half a million distant quasars, bright galaxies powered by the activity of the supermassive black holes at their cores. These sources are used to define a reference frame for the celestial coordinates of all objects in the Gaia catalogue, something that is routinely done in radio waves but now for the first time is also available at optical wavelengths.

I guarantee that many theories about specific strange stars, such as the plethora of different types of variable stars, are going to change drastically with this new and precise information. At the article they describe just one example relating to white dwarf stars.

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How to blow up a star

8:29 am

Link here. The story details the new supercomputer simulation work attempting to model the internal processes inside a dying star that cause it to explode as a supernova.

For more than half a century, physicists have suspected that the heat produced by elusive particles called neutrinos, created in the core of a star, could generate a blast that radiates more energy in a single second than the Sun will in its lifetime. But they have had trouble proving that hypothesis. The detonation process is so complex — incorporating general relativity, fluid dynamics, nuclear and other physics — that computers have struggled to mimic the mechanism in silico. And that poses a problem. “If you can’t reproduce it,” Janka says, “that means you don’t understand it.”

Now, improvements in raw computing power, along with efforts to capture the stellar physics in acute detail, have enabled substantial progress. Janka’s simulation marked the first time that physicists had been able to get a realistic 3D model of the most common type of supernova to explode. Just months later, a competing group based at Oak Ridge National Laboratory in Tennessee repeated the feat with a heavier, more complex star. The field is now buzzing, with more than half a dozen teams currently working on exploding stars in 3D.

They have apparently solved one problem, figuring out how the neutrino blast wave gets enough energy to blast free from the star’s core. A close read of the article indicates that, while progress has been made, they still have many gaps of their understanding.

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Zooming in on a Martian surprise

1:55 pm

Global map of Mars

Let’s take a journey. Above is a global map of Mars, showing its largest and well known geological features. While far smaller than Earth, its lack of oceans means that Mars’ actual dry surface has about the same square footage as the continents of Earth. It is a vast place. Getting a close look at every spot is going to take many decades of work, and probably won’t be finished until humans are actually walking its surface.

Let’s pick a spot, zoom in and find out what’s there.
» Read more

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SpaceX successfully launches NASA new exoplanet telescope

4:41 pm

Capitalism in space: SpaceX today successfully placed NASA’s new explanet space telescope, TESS, into orbit.

The first stage, which was making its first flight, successfully landed on the drone ship in the Atlantic. They hope to reuse this booster on a future Dragon launch.

Update: TESS’s solar arrays have successfully deployed.

The leaders in the 2018 launch standings:

11 China
8 SpaceX
4 ULA
3 Japan
3 Russia
3 Europe
3 India

The U.S. is now ahead of China, 12 to 11, in the national list.

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Diamonds from space!

9:46 am

Researchers have discovered nano-sized diamonds inside a recovered meteorite that suggest a formation process deep within a planet at least the size of Mercury.

The researchers used transmission electron microscopes to determine their composition and morphology, and found that the diamonds contained inclusions (impurities) made of chromite, phosphate and iron-nickel sulfides.

These inclusions are common in diamonds formed underground here on Earth, but this marks the first time they’ve been found in alien rocks. That’s interesting enough on its own, but it has much bigger implications – the team calculated that these diamonds could only have formed under pressure of more than 20 gigapascals. That means they must have been born inside a planet at least as big as Mercury, and possibly up to the size of Mars.

But there’s still more to the story. The fact these diamonds made it to Earth implies that their home planet, whatever it may have been, is no longer with us, since it would take quite a cataclysm to wrench them out of their birthplace deep underground and fling them into space. Instead, the team believes the diamonds came from a planetary embryo.

Not so fast. Though the researchers themselves, in the released paper, assume that the diamonds could only have formed from inside a now destroyed large planet, this leaves out the possibility that the diamonds formed inside one of the existing terrestrial planets, were moved upward toward the surface by later geological process (as happens to diamonds are here on Earth), and then were thrown from the planet by a later nearby impact. This scenario is just as likely.

Nonetheless, this discovery is fascinating. More than anything, it illustrates the inconceivable amount of time that has passed in creating our solar system. Any of these scenarios requires time, time in quantities that no human can really understand or conceptualize.

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How I spent my Saturday: Removing graffiti in a cave

11:40 am

Yesterday was another of my many cave adventures, but different than most. Instead of exploring and mapping newly discovered or out-of-the-way remote cave passages, I participated in a project of the Central Arizona Grotto (a chapter of the National Speleological Society and located in Phoenix) to remove years of graffiti from Peppersauce Cave. You can see pictures of yesterday’s effort here, published by the Arizona Star.

You won’t see any pictures of me. The younger cavers were far more photogenic.

Peppersauce has become what cavers call a “sacrificial cave.” It is open and ungated, relatively easy to traverse, and very well known throughout the state. Thus, many inexperienced people go there to see it, most of whom know little about caving, the ethics of protecting them, or the proper techniques for caving safely. Yesterday, while we were working to either sand-blast, chemically remove, or grind away old spray-paint (some of which was sadly obscene), I must have seen between 150 to 200 people go by. At least two thirds of them were not wearing helmets. Many clearly had never been in a cave before. Some were not wearing headlamps, carrying flashlights instead (which makes climbing harder because you don’t have use of both hands and can easily lose your light). A few even came in with no lights, depending instead on the lights their companions carried.

Because of this heavy traffic, Peppersauce has been badly trashed. On visits by experienced cavers we routinely carry out bags of trash, only to find that trash reappearing, sometime in mere hours. The walls of the cave had been covered with graffiti, some many layers deep.

Ray Keeler of Central Arizona Grotto (CAG) has organized several projects in the past to remove this graffitti over the past two decades. The effort he is leading this year is the third, and has the help of cavers from grottos throughout the state. This was the fourth clean-up weekend, and the first that I was able to attend (having missed the first three due to scheduling conflicts).

I’ve done similar things before, but never on this scale. It was quite educational using the solvent to remove some graffiti, but unfortunately many types of paint are completely resistant to removal by either sand-blasting or solvent. After awhile I got discouraged doing solvent work. Too often nothing got removed. In the afternoon I switched to our last technique, grinding, and was far more gratified with the results. The grinder, which we do not use on formations, removes only the slightest layer of material, and thus does little damage. It however is very effective in removing all paint, no matter how resistant.

The cave is now about two thirds cleaned. We are racing to finish the rest before the summer, because a typically insane reason forced upon us by the government. You see, according to a law passed by Congress, graffiti that is more than fifty years old is considered historical, and cannot be removed without a great deal of paperwork and complex bureaucracy. Spray paint was invented in the late 1960s (about fifty years ago), and so some of this ugly graffiti, no matter how obscene, is going to be protected by our government beginning later this year. Our goal is to get it removed beforehand, so that the cave can be returned to a more natural state, for future visitors to experience.

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The first sunspots of the next solar cycle

9:53 am

In linking to my sunspot update this week, there has been a lot of speculation at the climate website WattsUpWithThat that the next solar cycle has begun.

Our resident solar physicist, Dr. Leif Svalgaard commented and provided a link to something reported by his colleagues, something that likely would not have been possible without the fantastic solar observations of NASA’s Solar Dynamic Observeratory (SDO). He said: “Cycle 25 has already begun. It looks to me that SC25 will be a bit stronger than SC24, so probably no Grand Minimum this time.” It seems a small sunspot has been observed, that has the opposite polarity of cycle 24 sunspots. [emphasis in original]

The speculation at WattsUpWithThat, which suggested that this sunspot was the first such sunspot this cycle, was not quite accurate however. This sunspot with an opposite polarity, which decayed so quickly that it did not rate getting a sunspot number, was not the first. This week the Solar-Terrestrial Centre of Excellence, a Belgian organization focused on space-solar science, published this very good article discussing not only this sunspot but two others, one of which occurred more than a year ago.
» Read more

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More delays threaten the Thirty Meter Telescope in Hawaii

9:48 pm

The coming dark age: The delaying tactics of the opponents to building the Thirty Meter Telescope in Hawaii has caused the consortium to announce that it now seriously considering moving the telescope to Spain’s Canary Islands.

These have been the most recent delaying tactics:

On Thursday, the Hawaii Senate approved a bill to ban new construction atop Mauna Kea, and included a series of audits and other requirements before the ban could be lifted. But House leaders said they don’t have plans to advance the bill. Democratic House Speaker Scott Saiki told the Honolulu Star-Advertiser that the “bill is dead on arrival in the House.”

There are also two appeals before the Hawaii Supreme Court. One challenges the sublease and land use permit issued by the Hawaii Board of Land and Natural Resources. The other has been brought by a Native Hawaiian man who says use of the land interferes with his right to exercise cultural practices and is thus entitled to a case hearing.

When the telescope gets moved, expect these barbarians in Hawaii to celebrate loudly, claiming their victory as a victory for “native rights.” What they will really be telling us is two things. First, they are against gaining new knowledge and new technology in a manner that does no one any harm. And two, they put racial rights above all, making them the worst sort of bigots.

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Is it a volcano or an impact crater? Mars Express wants to know!

9:58 am

Europe’s Mars Express orbiter has taken a high resolution image of Ismenia Patera, a very large crater located in the Arabia Terra region of Mars, the largest part of the transition zone between the low flat northern plains and the high rough southern terrain.

The crater is intriguing to scientists because they are not sure if it was created by an impact, or a volcano.

Certain properties of the surface features seen in Arabia Terra suggest a volcanic origin: for example, their irregular shapes, low topographic relief, their relatively uplifted rims and apparent lack of ejected material that would usually be present around an impact crater.

However, some of these features and irregular shapes could also be present in impact craters that have simply evolved and interacted with their environment in particular ways over time.

There is also additional evidence that this region was once home to volcanic activity. If so, that activity would have changed the terrain, and thus made its geological history more complex and difficult to decipher, a fact that is important since this is also a region that might have been at the edge of theorized northern Martian Ocean.

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Jupiter’s North Pole, as seen in infrared by Juno

9:06 am

The Juno science team has released an animation that shows, in infrared and in three dimensions, the storms of Jupiter’s north pole.

The link has three videos. One shows the gas giant’s surprisingly irregular magnetic field, as found by Juno. The first and third show a low and a high fly-over of the north pole, in infrared. I have embedded both fly-overs below the fold. First watch the high fly-over, which is the first video. This will make the low fly-over more understandable as it flies over the eight smaller storms that encircle the pole’s central vortex.
» Read more

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A Martian snake of collapsed hills

10:21 am

A Martian snake of collapsed hills

Close-up of collapsed hills

Time to once again delve into this month’s release of high resolution images from Mars Reconnaissance Orbiter. The image above, cropped, rotated, and reduced in resolution to post here, shows a string of strange mounds or hills, each with similar collapse features on their tops. If you click on the picture, you can see the full resolution image, rotated properly with north up. You can also go to the MRO post, which provides some additional information.

The white box indicates the location of the cropped close-up, at full resolution, to the right. This area is typical across the entire snake-like ridge. You have these mounds or hills, each with chaotic depressions at their tops. The depressions suggest that this ridge follows an underground void, like a lava tube. The ridge-like nature of the line of hills also suggest that this tube has been exposed by erosion over time, with the surrounding terrain more easily blown or washed away while the more resistant ridge remains.

At the same time, the line of hills is baffling. Why would a lava tube expand periodically to form something that looks like a string of pearls?

The location of this snaking ridge provides some additional context.
» Read more

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Issue with thermometers on Parker Solar Probe

8:56 am

As NASA prepares the Parker Solar Probe for its summer launch, engineers are reviewing an issue with the spacecraft’s thermometers.

As those preparations continue, officials are studying problems with devices known as platinum resistance thermometers that are part of the spacecraft’s thermal control system. Those devices have suffered a higher-than-expected failure rate, according to a presentation at an April 5 meeting of NASA’s Heliophysics Advisory Committee.

The thermometers are lightweight, highly sensitive temperature sensors used to help provide feedback to the spacecraft’s cooling system and solar arrays, NASA spokesman Dwayne Brown said April 9. “We put all spacecraft through a rigorous test program to make sure all systems are working as designed and it is normal for a test program to uncover issues.”

“The team is looking very carefully at whether any change is needed,” Peg Luce, acting director of NASA’s heliophysics division, said at the meeting. The issue, she said, was debated “quite significantly” at a review last week to approve the shipment of the spacecraft to Florida, including whether to delay that shipment to study the problem. “There are certain, possible fixes if we need to fix something that could be done at the Cape, so the decision was to go ahead and ship,” she said.

This issue is especially critical as the spacecraft is intended to fly as close as four million miles from the Sun. If these thermometers fail too easily, the spacecraft will not be able to monitor its temperature properly, and it will likely fail much sooner than planned.

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Europe’s Trace Gas Orbiter achieves operational orbit around Mars

8:33 am

After a year of aerobraking to lower its orbit, the European Space Agency’s Trace Gas Orbiter has reached its planned orbit around Mars, and is about to begin studying the red planet’s atmosphere.

The primary goal is to take a detailed inventory of trace gases – those that make up less than 1% of the total volume of the planet’s atmosphere. In particular, the orbiter will seek evidence of methane and other gases that could be signatures of active biological or geological activity.

On Earth, living organisms release much of the planet’s methane. It is also the main component of naturally occurring hydrocarbon gas reservoirs, and a contribution is also provided by volcanic and hydrothermal activity. Methane on Mars is expected to have a rather short lifetime – around 400 years – because it is broken down by ultraviolet light from the Sun. It also reacts with other species in the atmosphere, and is subject to mixing and dispersal by winds. That means, if it is detected today, it was likely created or released from an ancient reservoir relatively recently. Previous possible detections of methane by ESA’s Mars Express and more recently by NASA’s Curiosity rover have been hinted at, but are still the subject of much debate.

The Trace Gas Orbiter can detect and analyse methane and other trace gases even in extremely low concentrations, with an improved accuracy of three orders of magnitude over previous measurements. It will also be able to help distinguish between the different possible origins. [emphasis mine]

The highlighted sentence is important. Pinpointing a region where methane is concentrated will allow scientists to better understand where it is coming from, and what is causing its release. It could be microbiological life, but it also could be from active volcanic processes. Finding either or both would be significant, to put it mildly.

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Sunspot update for March 2018: the sun crashes!

11:49 am

It surely looks like the solar minimum has arrived, and it has done so far earlier than expected! On Sunday NOAA posted its monthly update of the solar cycle, covering sunspot activity for March 2018. Below is my annotated version of that graph.

March 2018 was the least active month for sunspots since the middle of 2009, almost nine years ago. In fact, activity in the past few months has been so low it matches the low activity seen in late 2007 and early 2008, ten years ago when the last solar minimum began and indicated by the yellow line that I have added to the graph below. If the solar minimum has actually arrived now, this would make this cycle only ten years long, one of the shortest solar cycles on record. More important, it is a weak cycle. In the past, all short cycles were active cycles. This is the first time we have seen a short and weak cycle since scientists began tracking the solar cycle in the 1700s, following the last grand minimum in the 1600s when there were almost no sunspots.
» Read more

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Revisiting Biosphere 2

1:22 pm

Biosphere 2

This week Diane and I have a friend visiting from back east. As locals generally do when guests visit, we used this visit as an excuse to go sightseeing at local attractions that we somehow never got the time to visit on our own.

So on Tuesday we drove north to take a tour of Biosphere 2, what has been called “a giant space-age ark in the middle of the desert.” The idea, as sold heavily to the public when it was built in the late 1980s and early 1990s, was that eight people would try to live in a closed system for two years, demonstrating the technology needed to both build colonies on other worlds as well as protect the environment here on Earth.

The system wasn’t really closed however (power came from outside), and during the first two year mission it seemed they were somewhat lax about keeping the system closed.

One Biospherian accidentally cut off the tip of her finger and left for medical care. When she returned, she carried in two duffle bags of supplies to the supposedly self-sustaining environment (which presumably would not have been feasible on, say, Mars).

There were also financial issues, as mentioned by our tour guide and confirmed by news stories. Its backer, Texas oil man Edward Bass, spent somewhere between $150 to $200 million. It seems however that the managers running Biosphere 2 didn’t keep good books, and when Bass asked for an accounting they couldn’t provide it. Instead, they attempted to sabotage the project’s second mission.
» Read more

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A spray of volcanic ejecta on Mars?

10:38 am

pit features on floor of crater

Time for some more weird Mars geology! Today the science team for the high resolution camera on Mars Reconnaissance Orbiter released its monthly batch of new images. There is a lot of interesting stuff buried therein, some of which I will feature periodically in the next month.

The image on the right, reduced in resolution to post here, is a good example. (If you click on the image you can see the full resolution version.) It shows a scattering of pits in three specific areas on the crater floor, all in a line going from the northeast to the southwest. Yet, the rest of the crater floor lacks similar pits, and is either very smooth or has a mottled appearance. Both the smooth and the mottled areas appear to have a very faint trend going from the northwest to the southeast, which to my eye appears caused by the general wind direction that flows across the crater floor.

Even more intriguing, the pits in these three areas appear to be mostly oblong and also trend from the northeast to the southwest, cutting across the general trend of the rest of the crater floor. You can see this in the cropped closeups from the full resolution image below, showing the two boxed areas indicated on the image on the right.
» Read more

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Astronomers find a dozen black holes near center of Milky Way

8:40 am

Astronomers have discovered a dozen smaller black holes orbiting near Sagittarius A* (pronounced “A-star”), the supermassive black hole at the center of the Milky Way.

Charles Hailey from Columbia University in New York and colleagues used archival data from Nasa’s Chandra X-ray telescope to come to their conclusions. They report the discovery of a dozen inactive and low-mass “binary systems”, in which a star orbits an unseen companion – the black hole.

The supermassive black hole at the centre of the Milky Way, known as Sagittarius A* (Sgr A*), is surrounded by a halo of gas and dust that provides the perfect breeding ground for the birth of massive stars. These stars live, die and could turn into black holes there. In addition, black holes from outside the halo are believed to fall under the influence of Sgr A* as they lose their energy, causing them to be pulled into its vicinity, where they are held captive by its force. Some of these bind – or “mate” – to passing stars, forming binary systems.

They have extrapolated their data to predict the existence of thousands more of these small black holes near the galaxy’s center.

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Sightseeing

8:48 am

Biosphere-2

Posting has been light the past few days, and will be today, because we have a friend visiting from back east. This of course provides an excuse to do some sightseeing. Yesterday we visited Biosphere-2, the first time I have ever been there, as shown in the picture above. Today we are heading down to Bisbee, Arizona.

I plan to write up my impressions of Biosphere-2 tomorrow. Stay tuned!

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Near the Martian shoreline

1:20 pm

One of the prime areas of research for Mars planetary geologists is the region on Mars where the geography appears to transition from the southern cratered, rough terrain to the northern low, generally smooth, and flat plains. It is theorized by some scientists that the northern plains were once an ocean, probably shallow and probably intermittent, but wet nonetheless for considerable periods. The global map of Mars below, created by the laser altimeter on Mars Global Surveyor, clearly shows the obvious elevation differences between the low northern plans (blue) and the high, more cratered southern regions (changing from yellow to orange as you move higher).

Labeled global Map of Mars

Scientists have spent a considerable effort studying this transition zone (green on the map), illustrated by just one example I recently highlighted, showing that, though there does not appear to be a clear shoreline in many places, there is strong evidence that a shallow ocean repeatedly rose and fell in this transition zone, leaving behind geological ripple marks vaguely reminiscent of those seen on a beach caused by the rise and fall of the tides.

Today we highlight another example, taken in January 2018 at the location indicated by the cross on the above map.
» Read more

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Hubble finds galaxy with no evidence of dark matter

12:29 pm

The uncertainty of science: Using the Hubble Space Telescope astronomers have discovered a nearby galaxy that apparently has little or no evidence of dark matter.

The unique galaxy, called NGC 1052-DF2, contains at most 1/400th the amount of dark matter that astronomers had expected. The galaxy is as large as our Milky Way, but it had escaped attention because it contains only 1/200th the number of stars. Given the object’s large size and faint appearance, astronomers classify NGC 1052-DF2 as an ultra-diffuse galaxy. A 2015 survey of the Coma galaxy cluster showed these large, faint objects to be surprisingly common.

But none of the ultra-diffuse galaxies discovered so far have been found to be lacking in dark matter. So even among this unusual class of galaxy, NGC 1052-DF2 is an oddball.

Van Dokkum and his team spotted the galaxy with the Dragonfly Telephoto Array, a custom-built telescope in New Mexico they designed to find these ghostly galaxies. They then used the W.M. Keck Observatory in Hawaii to measure the motions of 10 giant groupings of stars called globular clusters in the galaxy. Keck revealed that the globular clusters were moving at relatively low speeds, less than 23,000 miles per hour. Stars and clusters in the outskirts of galaxies containing dark matter move at least three times faster. From those measurements, the team calculated the galaxy’s mass. “If there is any dark matter at all, it’s very little,” van Dokkum explained. “The stars in the galaxy can account for all the mass, and there doesn’t seem to be any room for dark matter.”

The galaxy is unusual in many other ways.

The Hubble images also revealed the galaxy’s unusual appearance. “I spent an hour just staring at the Hubble image,” van Dokkum recalled. “It’s so rare, particularly these days after so many years of Hubble, that you get an image of something and you say, ‘I’ve never seen that before.’ This thing is astonishing: a gigantic blob that you can look through. It’s so sparse that you see all of the galaxies behind it. It is literally a see-through galaxy.”

The ghostly galaxy doesn’t have a noticeable central region, or even spiral arms and a disk, typical features of a spiral galaxy. But it doesn’t look like an elliptical galaxy, either. The galaxy also shows no evidence that it houses a central black hole. Based on the colors of its globular clusters, the galaxy is about 10 billion years old. Even the globular clusters are oddballs: they are twice as large as typical stellar groupings seen in other galaxies.

The bottom line here is that we have only circumstantial evidence that dark matter exists, based solely on the fact that in all other measured galaxies, the outer stars rotate much faster than they should. That rotation speed however does not guarantee the existence of dark matter, only that something is causing the fast rotation. And the lack thereof in this galaxy puts a big crimp in the theory that dark matter exists, since the theories that posit its existence almost require it to be present in every galaxy.

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The James Webb Telescope: a signpost for identifying fake news sources

11:35 am

The news yesterday that NASA will once again have to delay the launch of the James Webb Space Telescope due to a variety of technical issues and management errors not only exemplified the fundamental failure of the federal government, it also illustrated the routine failures of today’s mainstream press.

First, Webb’s new delay epitomizes the systemic incompetence of Washington. Despite being 13 years behind schedule and costing eight times more than originally planned, NASA and its contractors still couldn’t get things right.

Most of the problems have occurred with the spacecraft half of the project, which was built by Northrop Grumman in California and is undergoing testing there. During the teleconference, NASA officials, including acting Administrator Robert Lightfoot, expanded upon technical problems first reported publicly by the agency’s inspector general last month.

These include leaky valves within the spacecraft’s propulsion system and difficulties encountered during deployment tests of the sun shield. Not only did the thin, five-layer sun shield snag during the deployment, but technicians also found seven tears up to 10cm long within the material. NASA and Northrop Grumman have identified fixes for these problems, but their repair has added months of delays to the project, and engineers cannot be sure that more issues will not crop up during further testing.

Such failures, in NASA and in all big federal projects in recent years, are hardly news. Only the willfully blind or those who support wasting tax dollars to distribute pork will deny they exist.

The failures of the federal government however is not the focus of this essay. Instead, the announcement yesterday and the coverage of it by the press provides us a perfect and very obvious signpost for differentiating between the fake news sources that are generally unreliable or too often allow their biases to influence their reporting, and those sources that do a good job.

That signpost is one simple fact: Webb is not a replacement or successor to the Hubble Space Telescope, despite NASA making this false claim for decades. Hubble is an optical telescope. Webb will view the universe in the infrared. These are too entirely different things.

Yet, too many news sources today repeated NASA’s false claim, illustrating how little they know about both telescopes and their design, while revealing their complete inability to do some basic journalistic research. Instead they merely rewrite old press releases, and thus prove clearly by their bad reporting why so many people have so little respect for the modern press.

The worst examples made this false claim right in the headline:
» Read more

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Webb telescope delayed again to 2020

10:34 am

NASA has announced that it is once again delaying the launch of the James Webb Space Telescope, from 2019 to 2020.

The observatory was supposed to fly this year. But last fall, NASA bumped the launch to 2019. NASA announced the latest delay on Tuesday. “We have one shot to get this right before going into space,” said Thomas Zurbuchen, NASA’s associate administrator of science. He said some mistakes were made while preparing the telescope, and NASA underestimated the scale of the job. [emphasis mine]

None of this is a surprise. Webb is more pork than science. It was originally budgeted at $1 billion, with a planned launch in 2011. It will now cost more than $9 billion, and be delayed almost a decade. Since the project began in the early 2000s, by the time it launches it will have been in development for almost two decades, which is almost a lifetime career for some people.

And note, the article includes the lie that Webb is “a successor to the Hubble Space Telescope.” It is not. Hubble is an optical telescope. Webb will only look in the infrared. These are very different things.

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Tabby’s Star dims again

8:37 am

Scientists studying Tabby’s Star have revealed that it suddenly dimmed last week, the most since 2013, and then just as quickly returned almost to normal.

The latest dimming event started with a slow decline and ended with a rapid increase in brightness, Boyajian and her team wrote on their blog. Dust from a backward comet tail and then larger chunks from the broken-up body would explain that uneven pattern.

At this time the evidence clearly points not to alien megastructures but to clouds of fine dust whose structure and origin remain puzzling.

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India delays Chandrayaan-2 six months

5:46 pm

Because engineers wished more time, India has delayed the launch of its second unmanned Moon mission, Chandrayaan-2, from April to October.

Union Minister of State in the Prime Minister’s Office, in-charge of the Department of Space, Jitendra Singh had on 16 February last said the lunar mission under which the Isro will for the first time attempt to land a rover on the moon’s south pole, will be launched in April.

Sivan (head of ISRO) had earlier said the window to launch the Rs800 crore mission was between April and November 2018. While the “targeted date” was April, Isro would launch the mission in October or November, he had said.

This is a very ambitious mission, so pushing the launch back to October seems quite reasonable. That they are aiming for the south pole is also smart, especially since NASA has abandoned that location as a target to instead build a giant Potemkin village orbiting the Moon, where it can accomplish nothing.

Posted between Flagstaff and Phoenix as we head back from a very successful four-day caving expedition in the Grand Canyon.

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Mars rover update: March 21, 2018

2:10 pm

Summary: Curiosity continues its exploration of Vera Rubin Ridge, including several drilling attempts. Opportunity is halfway down Perseverance Valley.

For a complete list of all past updates going back to July 2016, see my February 8, 2018 update.

Curiosity

Curiosity's traverse map, Sol 1993

For the overall context of Curiosity’s travels, see Pinpointing Curiosity’s location in Gale Crater.

Since my February 8, 2018 update, the Curiosity science team has apparently been loath to leave Vera Rubin Ridge. They had begun the trek to the northeast that would take them towards the exit ridge heading to the southeast, as indicated by the dotted red line on the traverse map above, but then continued past that planned route to continue to the northeast. Along the way they attempted to drill twice using an improvised approach that they hoped would bypass the drill’s stuck feed mechanism, without apparent success.

The panorama below is looking to the west and south, as indicated by the yellow lines in the image above.
» Read more

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Star’s close approach 70,000 years ago pinned to cometary orbits

10:03 am

Astronomers now think they have pinned the orbits of about 340 comets to another star’s close approach to our solar system 70,000 years ago.

About 70,000 years ago, when the human species was already on Earth, a small reddish star approached our solar system and gravitationally disturbed comets and asteroids. Astronomers from the Complutense University of Madrid and the University of Cambridge have verified that the movement of some of these objects is still marked by that stellar encounter. At a time when modern humans were beginning to leave Africa and the Neanderthals were living on our planet, Scholz’s star – named after the German astronomer who discovered it – approached less than a light-year from the Sun. Nowadays it is almost 20 light-years away, but 70,000 years ago it entered the Oort cloud, a reservoir of trans-Neptunian objects located at the confines of the solar system.

This discovery was made public in 2015 by a team of astronomers led by Professor Eric Mamajek of the University of Rochester (USA). The details of that stellar flyby, the closest documented so far, were presented in The Astrophysical Journal Letters.

Now two astronomers from the Complutense University of Madrid, the brothers Carlos and Raúl de la Fuente Marcos, together with the researcher Sverre J. Aarseth of the University of Cambridge (United Kingdom), have analyzed for the first time the nearly 340 objects of the solar system with hyperbolic orbits (very open V-shaped, not the typical elliptical), and in doing so they have detected that the trajectory of some of them is influenced by the passage of Scholz´s star.

It is likely that the close approach influenced a lot more objects, many of which might not have yet arrived in the inner solar system. Moreover, their computer models suggest that the star might have come closer to the Sun than 0.6 light years.

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New theory suggests Mars’ oceans formed earlier and intermittently

11:19 am

Scientists have proposed a new model for the existence of oceans on Mars’ northern plains that proposes they formed earlier, were shallower, were variable in size, and formed in conjunction with the eruptions that formed the planet’s giant volcanoes.

The proposal by UC Berkeley geophysicists links the existence of oceans early in Mars history to the rise of the solar system’s largest volcanic system, Tharsis, and highlights the key role played by global warming in allowing liquid water to exist on Mars. “Volcanoes may be important in creating the conditions for Mars to be wet,” said Michael Manga, a UC Berkeley professor of earth and planetary science and senior author of a paper appearing in Nature this week and posted online March 19.

…The new model proposes that the oceans formed before or at the same time as Mars’ largest volcanic feature, Tharsis, instead of after Tharsis formed 3.7 billion years ago. Because Tharsis was smaller at that time, it did not distort the planet as much as it did later, in particular the plains that cover most of the northern hemisphere and are the presumed ancient seabed. The absence of crustal deformation from Tharsis means the seas would have been shallower, holding about half the water of earlier estimates. “The assumption was that Tharsis formed quickly and early, rather than gradually, and that the oceans came later,” Manga said. “We’re saying that the oceans predate and accompany the lava outpourings that made Tharsis.”

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Scientists theorize that Oumuamua came from a binary star system

8:17 am

Based on statistics and computer modeling, some scientists believe that the interstellar object Oumuamau likely came from stellar binary system.

For the new study, published in the journal Monthly Notices of the Royal Astronomical Society, Jackson and his co-authors set about testing how efficient binary star systems are at ejecting objects. They also looked at how common these star systems are in the Galaxy. They found that rocky objects like ‘Oumuamua are far more likely to come from binary than single star systems. They were also able to determine that rocky objects are ejected from binary systems in comparable numbers to icy objects.

Their conclusion does make sense, though any good scientist would retain a gigantic sense of skepticism. While it is statistically reasonable to conclude that a majority of interstellar objects should come from binary systems, there is no guarantee that Oumuamua in particular did so. Even if the odds were one in a million, there is always that one, and the universe often seems prone to fooling us.

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North American mountains get 3Xs the snow previously estimated

8:30 am

The uncertainty of science: A new analysis based on computer models suggests that the mountains of North America get three times more snow each year than scientists has previously estimated.

Those figures come thanks to a new analysis in which researchers used computer simulations to estimate the typical annual snowfall in each of 11 North American mountain ranges. After supercomputer simulations of regional climate that would have taken 50 years on the average laptop, the team found that those mountain ranges receive about 3018 cubic kilometers of snow a year. Although those ranges together cover only about 25% of the area stretching from the Arctic Ocean down to Mexico’s southern border, they get about 60% of its snow, the researchers report in Geophysical Research Letters. That’s nearly three times the estimate for mountain snow from one previous study, the team notes.

First, this is based on computer simulations, not actual data in the field. I wouldn’t put much money on it. Second, it does show us how little climate scientists really know about the climate, as this simulation is still using all the knowledge they have, and it comes up with a conclusion that confounds them. Third, I was astonished the article didn’t try to push the idea that this larger estimate should be blamed on human-caused global warming. It didn’t, which I suppose is a sign of some progress.

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