EPA approves release of bacteria-carrying mosquitoes to 20 states

The EPA has approved the release of lab-grown male mosquitoes, carrying a bacteria that prevents reproduction, in 20 states.

MosquitoMate will rear the Wolbachia-infected A. albopictus mosquitoes in its laboratories, and then sort males from females. Then the laboratory males, which don’t bite, will be released at treatment sites. When these males mate with wild females, which do not carry the same strain of Wolbachia, the resulting fertilized eggs don’t hatch because the paternal chromosomes do not form properly.

The company says that over time, as more of the Wolbachia-infected males are released and breed with the wild partners, the pest population of A. albopictus mosquitoes dwindles. Other insects, including other species of mosquito, are not harmed by the practice, says Stephen Dobson, an entomologist at the University of Kentucky in Lexington and founder of MosquitoMate.

While caution should always be exercised when introducing something like this into the environment, I honestly can’t see any downside to this work. The lab-grown mosquitoes cannot spread, as they cannot reproduce, even as their introduction reduces the mosquito population.

Nonetheless, no one should be surprised that this project has met with political resistance in many places.

First infrared image of a red giant star with a mass of the sun

 W Hydrae

Astronomers have used the ALMA array in Chile to take the first infrared image of a red giant star that has a mass similar to the Sun.

The dotted ring in the the image, cropped to post here, shows the Earth’s orbit. The star is farther along in its evolution than the Sun, and has expanded as it begins to use up its nuclear fuel.

The observations have also surprised the scientists. The presence of an unexpectedly compact and bright spot provides evidence that the star has surprisingly hot gas in a layer above the star’s surface: a chromosphere. “Our measurements of the bright spot suggest there are powerful shock waves in the star’s atmosphere that reach higher temperatures than are predicted by current theoretical models for AGB stars,” says Theo Khouri, astronomer at Chalmers and member of the team.

An alternative possibility is at least as surprising: that the star was undergoing a giant flare when the observations were made.

The handful of infrared images that astronomers have taken so far of several red giant stars indicates that these stars no longer look like the Sun, with a clear and precise spherical shape, but are puffed up almost like a cloud, with many uneven layers and complex extensions produced by their chaotic nature. This image of W Hydrae reinforces this impression.

New Horizons wants the public to help pick a nickname for its next target

The New Horizons science team is asking the public to submit suggestions for a good nickname for 2014 MU69, the Kuiper Belt object that the spacecraft will fly past on January 1, 2019.

The naming campaign is hosted by the SETI Institute of Mountain View, California, and led by Mark Showalter, an institute fellow and member of the New Horizons science team. The website includes names currently under consideration; site visitors can vote for their favorites or nominate names they think should be added to the ballot. “The campaign is open to everyone,” Showalter said. “We are hoping that somebody out there proposes the perfect, inspiring name for MU69.”

The campaign will close at 3 p.m. EST/noon PST on Dec. 1. NASA and the New Horizons team will review the top vote-getters and announce their selection in early January.

The press release says that a more formal name for the object will be submitted to the IAU after the fly-by.

NASA forces retraction of astronaut vision study due to privacy issues

NASA has forced the retraction of an important science paper researching the damage to vision for astronauts on long spaceflights because of a concern the privacy of the astronauts might be violated.

According to the first author, the paper included information that could identify some of the astronauts that took part in the study — namely, their flight information. Although the author said he removed the identifying information after the paper was online, NASA still opted to retract it. But a spokesperson at NASA told us the agency did not supply the language for the retraction notice. The journal editor confirmed the paper was retracted for “research subject confidentiality issues,” but referred a question about who supplied the language of the notice back to NASA.

…According to first author Noam Alperin of the University of Miami Miller School of Medicine in Florida, the paper “Role of Cerebral Spinal Fluid in Space Flight Induced Ocular Changes and Visual Impairment in Astronauts” showed that visual damage caused by long space flights resulted from tiny shifts in the volume of spinal fluid — not vascular changes, as many experts had previously thought.

Protecting the health privacy of the astronauts is something NASA and the doctors that work with them are legally required to do. However, in this case the paper had been scrubbed of this information a long time ago. To force its retraction now when the actual. research was valid and important and the privacy of the astronauts was now protected seems an over reaction to me. Then again, NASA might be under legal pressure from the astronauts themselves, and thus forced to act.

Sunspot update for October 2017

NOAA today posted its monthly update of the solar cycle, covering sunspot activity for October. That graph is posted below, with annotations.

October 2017 Solar Cycle graph

The graph above has been modified to show the predictions of the solar science community. The green curves show the community’s two original predictions from April 2007, with half the scientists predicting a very strong maximum and half predicting a weak one. The red curve is their revised May 2009 prediction.

After two straight months of rising sunspot activity, the number of sunspots plunged in October, returning the numbers almost exactly back to the general trend we have seen since 2014 when the solar maximum ended. While the short two month increase indicated that the minimum will not occur as soon as this long term trend suggests, the quick return to that trend this month suggests that it will.

Meanwhile, November is six days old and has yet to see any sunspots at all.

Astronomers find Kuiper Belt-like ring around Proxima Centauri

Worlds without end: Astronomers have found a dusty ring 1 to 4 astronomical units from the nearest star, Proxima Centauri.

Because Proxima Centauri is a smaller, dimmer star, its system is more compact. Proxima b [the star’s known exoplanet] circles the star at 0.05 astronomical units (a.u., the average distance between Earth and the Sun) — for reference, Mercury orbits the Sun at 0.39 a.u. The dusty ring lies well beyond that, extending from 1 to 4 a.u.

The Proxima ring is similar in some ways to the Kuiper Belt, a cold, dusty belt in the far reaches of our solar system (beyond 40 a.u.) that contains a fraction of Earth’s mass. While the Kuiper belt is well known for larger members such as Pluto and Eris, it also contains fine grains, ground down through collisions over billions of years. The dust ALMA observed around Proxima Centauri is composed of similar small grains. The average temperature and total mass of the Proxima ring is also about the same as our Kuiper Belt.

Because the ring here much closer to the star than our Kuiper Belt, the material is much more densely packed. Moreover, the presence of both a ring and an exoplanet suggests more planets might remain undiscovered there, increasing the chances that this star could have a solar system very worthwhile exploring.

Fifth mirror for Giant Magellan Telescope has been cast

The fifth mirror, out of seven, for Giant Magellan Telescope (GMT) has been cast by the University of Arizona mirror lab.

With its casting this weekend, the fifth GMT mirror joins three additional GMT mirrors at various stages of production in the Mirror Lab. Polishing of mirror 2’s front surface is well underway; coarse grinding will begin on the front of the third mirror shortly and mirror number 4, the central mirror, will soon be ready for coarse grinding following mirror 3. The first GMT mirror was completed several years ago and was moved to a storage location in Tucson this September, awaiting the next stage of its journey to Chile. The glass for mirror 6 has been delivered to Tucson and mirror seven’s glass is on order from the Ohara factory in Japan.

In time, the giant mirrors will be transported to GMT’s future home in the Chilean Andes at the Carnegie Institution for Science’s Las Campanas Observatory. This site is known for being one of the best astronomical sites on the planet with its clear, dark skies and stable airflow producing exceptionally sharp images. GMTO has broken ground in Chile and has developed the infrastructure on the site needed to support construction activities.

If all goes right, GMT will begin its science work using 4 mirrors in 2020, with the use of all 7 mirrors beginning in 2022. This will be several years before the larger Thirty Meter Telescope and the European Extremely Large Telescope.

Physicists using cosmic rays find hidden void inside the Great Pyramid

Physicists using cosmic rays detectors have located what appears to be an empty space inside the Great Pyramid in Egypt that has never been entered.

To see through the Great Pyramid, the researchers used a technique developed in high-energy particle physics: they tracked particles called muons, which are produced when cosmic rays strike atoms in the upper atmosphere. Around 10,000 muons rain down on each square metre of Earth’s surface every minute. Sensitive muon detectors have been developed for use in particle accelerators, but they have also been used in the past decade or so to determine the inner structures of volcanoes and to study the damaged nuclear reactor at Fukushima, Japan.

In December 2015, physicist Kunihiro Morishima of Nagoya University, Japan, and his colleagues placed a series of detectors inside the Queen’s chamber, where they would detect muons passing through the pyramid from above. The particles are partially absorbed by stone, so any large holes in the pyramid would result in more muons than expected hitting the detectors.

After several months, “we had an unexpected line”, says Tayoubi. To check the result, two other teams of physicists, from the Japanese High Energy Accelerator Research Organization in Tsukuba and the French Alternative Energies and Atomic Energy Commision in Paris, then used different types of muon detector placed in other locations both inside and outside the pyramid. All three teams observed a large, unexpected void in the same location above the Grand Gallery. …The space is at least 30 metres long, with a similar cross section to the Grand Gallery. “It was a big surprise,” says Tayoubi. “We’re really excited.”

It is unclear how or even if they will access this void. Right now its purpose remains a mystery, including whether it contains any artifacts.

NASA wants private company to take over Spitzer Space Telescope

NASA has issued a request for proposals from private companies or organizations to take over the operation of the Spitzer Space Telescope after 2019.

NASA’s current plans call for operating Spitzer through March of 2019 to perform preparatory observations for the James Webb Space Telescope. That schedule was based on plans for a fall 2018 launch of JWST, which has since been delayed to the spring of 2019. Under that plan, NASA would close out the Spitzer mission by fiscal year 2020. That plan was intended to save NASA the cost of running Spitzer, which is currently $14 million a year. The spacecraft itself, though, remains in good condition and could operating well beyond NASA’s current plan.

“The observatory and the IRAC instrument are in excellent health. We don’t have really any issues with the hardware,” said Lisa Storrie-Lombardi, Spitzer project manager, in a presentation to the committee Oct. 18. IRAC is the Infrared Array Camera, an instrument that continues operations at its two shortest wavelengths long after the spacecraft exhausted the supply of liquid helium coolant.

The spacecraft’s only consumable is nitrogen gas used for the spacecraft’s thrusters, and Storrie-Lombardi said the spacecraft still had half its supply of nitrogen 14 years after launch.

The way a private organization could make money on this is to charge astronomers and research projects for observation time. This could work, since there is usually a greater demand for research time than available observatories.

New exoplanet defies accepted theories of planet formation

The uncertainty of science: A newly discovered exoplanet, the size of Jupiter and orbiting a star half the size of the Sun, should not exist based on all the presently favored theories of planet formation.

New research, led by Dr Daniel Bayliss and Professor Peter Wheatley from the University of Warwick’s Astronomy and Astrophysics Group, has identified the unusual planet NGTS-1b – the largest planet compared to the size of its companion star ever discovered in the universe.

NGTS-1b is a gas giant six hundred light years away, the size of Jupiter, and orbits a small star with a radius and mass half that of our sun.

Its existence challenges theories of planet formation which state that a planet of this size could not be formed by such a small star. According to these theories, small stars can readily form rocky planets but do not gather enough material together to form Jupiter-sized planets. The planet is a hot Jupiter, at least as large as the Jupiter in our solar system, but with around 20% less mass. It is very close to its star – just 3% of the distance between Earth and the Sun – and orbits the star every 2.6 days, meaning a year on NGTS-1b lasts two and a half days.

No one should be surprised by this. While the present theories of planet formation are useful and necessary, giving scientists a rough framework for studying exoplanets, they should not be taken too seriously. We simply do not yet have enough information about how stars, solar systems, and planets form.

Astronomers find 20 more exoplanet candidates in Kepler archive

Worlds without end: Astronomers reviewing the Kepler archive have found 20 more exoplanet candidates, including one that has a mass about 97 percent of the Earth with an orbit 395 days long circling a star like the Sun.

The planet would be colder than Earth, as its star is slightly cooler than the Sun, and its orbit is slightly farther away. Nonetheless, this is an amazing twin, and would certainly be a prime target when interstellar travel becomes routine.

An ancient ocean on Ceres?

Two studies released today by the Dawn science team suggest that the spacecraft has found evidence that an ancient ocean once existed on Ceres.

In one study, the Dawn team found Ceres’ crust is a mixture of ice, salts and hydrated materials that were subjected to past and possibly recent geologic activity, and this crust represents most of that ancient ocean. The second study builds off the first and suggests there is a softer, easily deformable layer beneath Ceres’ rigid surface crust, which could be the signature of residual liquid left over from the ocean, too.

Scientists propose adding smog to atmosphere to fight global warming

What could possibly go wrong? Global warming scientists have proposed injecting sulphate aerosols (another name for pollution) into the upper atmosphere in order to counter their predicted global temperature rise.

Experts are considering ploughing sulphate aerosols into the upper atmosphere which would cause some of the suns rays to be reflected back out into space. This could potentially cool the Earth down and help counter the effects of climate change, scientists say.

The move would also help reduce coral bleaching and help calm powerful storms.

James Crabbe, from the University of Bedfordshire, is leading the study and his initial results suggest the plan could help cool the planet.

This proposal is based on such flimsy science it appalls me that any scientist would even consider it, especially when you think about the unknown consequences.

Rosetta’s capture of a dust jet from Comet 67P/C-G

Dust jet on Comet 67P/C-G

Cool image time! The Rosetta science team has released images and data gathered in July 2016 when the spacecraft successfully observed a dust outburst erupting from Comet 67P/C-G’s surface. The image on the right, slightly reduced in resolution, shows that outburst.

When the Sun rose over the Imhotep region of Rosetta’s comet on July 3, 2016, everything was just right: As the surface warmed and began to emit dust into space, Rosetta’s trajectory led the probe right through the cloud. At the same time, the view of the scientific camera system OSIRIS coincidentally focused precisely on the surface region of the comet from which the fountain originated. A total of five instruments on board the probe were able to document the outburst in the following hours.

As should be expected, the results did not match the models or predictions. The jet, instigated by water-ice just below the surface turning into gas when heated by the Sun, was much dustier than predicted. They have theories as to why, but it appears that no one likes these theories that much.

The first large object identified coming from interstellar space

Astronomers think they have spotted the first large object to come from beyond the solar system.

Based on its apparent brightness, dynamicist Bill Gray calculates that it would have a diameter of about 160 meters (525 feet) if it were a rock with a surface reflectivity of 10%. “It went past the Sun really fast,” Gray notes, “and may not have had time to heat up enough to break apart.”

Now it’s headed out of the solar system, never to return. It passed closest to Earth on October 14th at a distance of about 24,000,000 km (15,000,000 miles), and astronomers worldwide have been tracking it in the hopes of divining its true nature — especially whether it’s displaying any cometary activity.

…According to Gray, Comet PanSTARRS appears to have entered the solar system from the direction of the constellation Lyra, within a couple of degrees of right ascension 18h 50m, declination +35° 13′. That’s tantalizingly close to Vega — and eerily reminiscent of the plot of the movie Contact — but its exact path doesn’t (yet) appear to link any particular star.

This object entered the solar system moving at 26 km (16 miles) per second. At that speed, in 10 million years it would traverse 8,200,000,000,000,000 km — more than 850 light-years.

Reminds me of a really good science fiction novel I read recently. They should keep an eye on it for as long as they can, just in case it suddenly changes course and settles into a more circular orbit around the Sun. In the unlikely case it does that, it might just be the biggest discovery in history.

Squiggles on Mars

Squiggles on Mars

Cool image time! The image on the right, reduced and cropped to post here, shows a sand dune slope with numerous squiggly troughs that end either in a small pit or slowly fade away. At first glance one things the troughs were caused by a boulder rolling downhill, but there are no boulders at the base of the slope, and a rolling boulder wouldn’t create so many similar squiggles like this.

The explanation is that the boulders are made of carbon dioxide ice.

Just like on Earth, high-latitude regions on Mars are covered with frost in the winter. However, the winter frost on Mars is made of carbon dioxide ice (dry ice) instead of water ice. We believe linear gullies are the result of this dry ice breaking apart into blocks, which then slide or roll down warmer sandy slopes, sublimating and carving as they go.

The linear gullies exhibit exceptional sinuosity (the squiggle pattern) and we believe this to be the result of repeated movement of dry ice blocks in the same path, possibly in combination with different hardness or flow resistance of the sand within the dune slopes.

For a really entertaining explanation of this process, take a look at the embedded video below the fold.
» Read more

Since 2016 almost a 1000 published papers have challenged the theory of human-caused climate change

Link here. What the author does is quote from numerous scientific papers where they either note the lack of evidence that human activity has caused the recent warming of the climate since the 1600s, or note other natural phenomenon where the evidence of influence is far stronger. Here’s one example:

Rosenblum and Eisenman, 2017

Observations indicate that the Arctic sea ice cover is rapidly retreating while the Antarctic sea ice cover is steadily expanding. State-of-the-art climate models, by contrast, typically simulate a moderate decrease in both the Arctic and Antarctic sea ice covers.

Here’s another, with a link to the actual peer-reviewed published paper:

Blaauw, 2017 [pdf]

This paper demonstrates that global warming can be explained without recourse to the greenhouse theory

He quotes many more, and has found 900 papers since 2016 that challenge the accepted-wisdoms pushed by global-warming theories.

The point here is not to say the climate doesn’t change, or that increased CO2 is not a concern, but to point out that the science is not settled, and anyone who makes that claim is either ignorant, or lying.

Engineers develop new technique to resume drill use on Curiosity

Engineers have successfully tested a new drill procedure on a duplicate rover on Earth that bypasses the problem in Curiosity’s drill.

The problem with the drill has been its feed mechanism, which pushes the drill bit downward as it drills its hole. The tests with the duplicate rover on Earth have instead had the drill bit fully extended and used the robot arm itself to push downward. It worked, but the problem on Mars is holding the drill bit perfectly straight and not slipping sideways. They are now doing a test with Curiosity to address this.

Curiosity touched its drill to the ground Oct. 17 for the first time in 10 months. It pressed the drill bit downward, and then applied smaller sideways forces while taking measurements with a force sensor. “This is the first time we’ve ever placed the drill bit directly on a Martian rock without stabilizers,” said JPL’s Douglas Klein, chief engineer for the mission’s return-to-drilling development. “The test is to gain better understanding of how the force/torque sensor on the arm provides information about side forces.”

This sensor gives the arm a sense of touch about how hard it is pressing down or sideways. Avoiding too much side force in drilling into a rock and extracting the bit from the rock is crucial to avoid having the bit get stuck in the rock.

Stay tuned for a Mars rover update, coming shortly!

The glory of Cassini’s Saturn

The glory of Saturn

Cool image time! The image on the right, reduced in resolution to post here, was taken by Cassini on August 17, 2017, one month before the spacecraft dived into Saturn to end its mission.

This view looks toward the sunlit side of the rings from about 19 degrees above the ringplane. The image was taken in green light with the Cassini spacecraft wide-angle camera on Aug. 12, 2017. Pandora was brightened by a factor of 2 to increase its visibility.

The view was obtained at a distance to Saturn of approximately 581,000 miles (935,000 kilometers) from Saturn. Image scale is 35 miles (56 kilometers) per pixel. The distance to Pandora was 691,000 miles (1.1 million kilometers) for a scale of 41 miles (66 kilometers) per pixel.

The moon Pandora can be seen in the full resolution image just beyond the outermost ring near the top of the screen.

Iranian scientist sentenced to death

An Iranian judge has sentenced an Iranian scientist to execution in 20 days.

The scientist, who appears to have mostly worked in Sweden, was convicted of spying for Israel. He in turn says he was railroaded because he refused to spy on his colleagues for the Iranian intelligence service.

What baffles me here is that he was arrested when returned to Iran for a short visit. He must have known that going back was going to put him in great risk. Why do it?

NASA instrument for European space telescope flawed and must be rebuilt

The NASA instrument for Europe’s Euclid optical/near-infrared space telescope has been found defective and must be rebuilt, thus delaying the launch of the telescope by at least one year.

What interested me about this telescope is its goals and specifications:

Euclid is a two-ton space telescope selected by ESA in 2011 as a medium-class mission in its Cosmic Vision program of space science missions. The spacecraft features a 1.2-meter telescope with visible and near-infrared instruments to study dark energy and dark matter, which combined account for about 95 percent of the universe. Euclid will operate at the Earth-sun L-2 Lagrange point, 1.5 million kilometers from Earth, that is used by other infrared astronomy missions.

With a mirror about half the size of Hubble’s, this telescope will act as a partial replacement and back up for it. In fact, it will likely make numerous ground-breaking discoveries, as every optical telescope placed above the atmosphere has so far done.

Meanwhile, the article provided no information on the flaws, who built the flawed instrument, and who will pay for the delays its failure will cause.

Juno’s first hints of Jupiter’s interior

Data from Juno not only suggests that the gas giant has a small fuzzy core, its storms appear to extend thousands of miles into the interior.

By studying Jupiter’s gravitational field, researchers can probe thousands of kilometres into the planet. On each close fly-by, Juno measures the planet’s complex gravitational tug. These observations have already revealed that Jupiter has a small, ‘fuzzy’, poorly defined core.

The latest results show that Jupiter’s gravitational field is askew, with different patterns in its northern and southern hemispheres, said Tristan Guillot, a planetary scientist at the Observatory of the Côte d’Azur in Nice, France. That suggests that its hydrogen-rich gas is flowing asymmetrically deep in the planet. “This is something that was not expected,” Guillot said at the meeting. “We were not sure at all whether we would be able to see that.”

Another clue to the structure of Jupiter’s interior came from how the gravity field varies with depth. Theoretical studies predict that the bigger the gravity signal, the stronger the flow of gas deep down. That information is important for teasing out whether all of Jupiter’s interior is rotating as a single solid body, or whether different layers spin separately from one another, like a set of nesting Russian dolls moving within each other.

Juno detected a gravity signal powerful enough to indicate that material is flowing as far down as 3,000 kilometres. “We’re just taking the clouds and the winds and extending them into the interior,” Kaspi said. Future work could help to pinpoint how strong the flow is at various depths, which could resolve whether Jupiter’s interior really resembles Russian dolls.

What is especially fascinating is that this first study of Jupiter shows it to appear so very different than Cassini’s first look at Saturn. Their polar regions are completely different, their storms are different, even their horizontal bands behave and look different. As I’ve said numerous times, the one given in planetary exploration is that every single planetary object we look at will be completely different from every other object.

NASA extends Dawn’s mission orbiting Ceres

NASA has decided to extend the Dawn mission again, but have that extension remain in orbit around Ceres.

A priority of the second Ceres mission extension is collecting data with Dawn’s gamma ray and neutron spectrometer, which measures the number and energy of gamma rays and neutrons. This information is important for understanding the composition of Ceres’ uppermost layer and how much ice it contains.

The spacecraft also will take visible-light images of Ceres’ surface geology with its camera, as well as measurements of Ceres’ mineralogy with its visible and infrared mapping spectrometer.

The extended mission at Ceres additionally allows Dawn to be in orbit while the dwarf planet goes through perihelion, its closest approach to the Sun, which will occur in April 2018. At closer proximity to the Sun, more ice on Ceres’ surface may turn to water vapor, which may in turn contribute to the weak transient atmosphere detected by the European Space Agency’s Herschel Space Observatory before Dawn’s arrival. Building on Dawn’s findings, the team has hypothesized that water vapor may be produced in part from energetic particles from the Sun interacting with ice in Ceres’ shallow surface.Scientists will combine data from ground-based observatories with Dawn’s observations to further study these phenomena as Ceres approaches perihelion.

They aim to get as close as 120 miles of the surface during this extension, half as close as the previous closest approach.

NASA and Australia sign extension of space-tracking agreement

NASA and Australia have signed an extension of the treaty that allowed for the construction and operation of antennas in Australia used by NASA’s Deep Space Network.

Australia’s ambassador to the US, Joe Hockey, signed the Space Tracking Treaty on behalf of Australia, with the acting administrator of NASA, Robert Lightfoot, signing on behalf of the US, at a ceremony at the Australian Embassy in Washington DC.

The treaty covers civil space facilities owned by NASA and located within Australia, including the Canberra Deep Space Communication Complex at Tidbinbilla, as well as facilities in Western Australia and the Northern Territory.

That the treaty signing was turned into a photo-op, something that previous signings did not require, suggests to me that Australia’s politicians are planning bigger things for their future space program.

Thirty mile cave on the Moon?

A new analysis of data from Japan’s Kaguya lunar orbiter suggests that one of the cave pits it found could be an entrance to a lava tube 30 miles long.

In 2009, the Kaguya probe found a large shaft with an opening about 50 meters in diameter in the Marius Hills area. The shaft descends about 50 meters beneath the surface.

The JAXA team analyzed data obtained from a lunar radar sounder on the probe that indicated an underground structure extended west from the shaft. The study confirmed that the cavern, likely created by volcanic activity, has not collapsed, and there is the possibility of ice or water existing in rocks within the cave, the team said.

Do a search on Behind the Black using the search terms “cave” and “moon” and you will see many images of this pit, taken by Lunar Reconnaissance Orbiter as a follow-up to the Kaguya mission.

Astronomers reduce estimate of still undiscovered dangerous asteroids

Astronomers have now reduced [pdf] their estimate of the number of still undiscovered dangerous Near Earth Asteroids (NEAs) that could impact the Earth from 100 to less than 40.

Observers have been cataloging potentially hazardous asteroids for decades. Based on the number of finds, the area of sky explored, and the limiting brightness our telescopes and cameras can reach, researchers can estimate what fraction of the NEA population has been detected so far and how many more objects lurk undiscovered. Harris has published numerous such estimates over the years. Recently he realized that his estimates have been plagued by a seemingly innocuous but nonetheless consequential round-off error. Once corrected, the estimated number of large (diameter > 1 kilometer) NEAs remaining to be discovered decreases from more than 100 to less than 40.

To put it mildly, there is a lot of uncertainty here. This also reminds me of the cavers’ joke question: “How many miles of unexplored passages does this cave have?”

Nearby asteroid orbits both the Earth and the Sun

Worlds without end: Astronomers have determined that a recently discovered object with a weird solar orbit that also has it loop around the Earth each year is an asteroid, not space junk.

The asteroid is dubbed 2016 HO3. What is most interesting about this story to me however was this tidbit:

“Of the near-Earth objects we know of, these types of objects would be the easiest to reach, so they could potentially make suitable targets for exploration,” said Veillet, director of the LBT Observatory. “With its binocular arrangement of two 8.4-meter mirrors, coupled with a very efficient pair of imagers and spectrographs like MODS, LBT is ideally suited to the characterization of these Earth’s companions.”

New findings from Cassini’s final months

Link here. Among a bunch of other interesting results, this one I found the most tantalizing:

The spacecraft’s Ion and Neutral Mass Spectrometer (INMS) returned a host of first-ever direct measurements of the components in Saturn’s upper atmosphere, which stretches almost to the rings. From these observations, the team sees evidence that molecules from the rings are raining down onto the atmosphere. This influx of material from the rings was expected, but INMS data show hints of ingredients more complex than just water, which makes up the bulk of the rings’ composition. In particular, the instrument detected methane, a volatile molecule that scientists would not expect to be abundant in the rings or found so high in Saturn’s atmosphere.

The results generally leave behind more questions than answers, but that is exactly why exploring the universe is so much fun.

Europe’s Trace Gas Orbiter detects clouds over Martian volcano

Europe’s Trace Gas Orbiter (TGO) has detected clouds over the western slopes of the giant Martian volcano Arsia Mons.

This is not a new discovery, merely a confirmation of many past observations, all of which suggest that water-ice glaciers once flowed down those western slopes, and that some of that ice remains trapped in underground caves and lava tubes there. Undeniably this region appears at present to be the most valuable real estate on Mars. It has caves where the first colonies can be more easily built. Those caves likely have water in them. And the location is near the equator, which is easier to reach and also makes the environment somewhat less hostile.

TGO is presently slowly aerobraking itself down to its planned science orbit, which it is expected to reach in 2018.

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