Science & TechnologyS

Jupiter

Kepler's first exoplanet has been confirmed, ten years after discovery

kepler 1658 system
This is an artist's illustration of the Kepler-1658 system, where Kepler-1658 b orbits an evolved subgiant star every 3.8 days.
Ten years after the Kepler Space Telescope launched and revolutionized exoplanet discovery, Kepler-1658 b has finally been confirmed as the first exoplanet that the mission ever detected.

It's taken so long because the initial estimate of Kepler-1658, the planet's host star, was wrong. This also made the size estimate for the planet incorrect as well, and both of them were underestimated.

The incorrect numbers contributed to confusion that made the planet candidate seem like a false positive, and it was set aside. Then, University of Hawai'i graduate student Ashley Chontos focused her first year graduate research project on re-analyzing host stars of Kepler planet candidates.

Together, Chontos and an international team of astronomers have a paper on the planet that has been accepted for publication in the Astronomical Journal.

"Our new analysis, which uses stellar sound waves observed in the Kepler data to characterize the star, demonstrated that the star is in fact three times larger than previously thought. This in turn means that the planet is three times larger, revealing that Kepler-1658 b is actually a hot Jupiter," Chontos said in a statement.

Comment: See also:


Sun

New insights into coronal mass ejections

Coronal Mass Ejection
© NASA/SDOA coronal mass ejection captured by NASA's Solar Dynamics Observatory in September, 2017.
An international team of astronomers has untangled new insight into the birth of coronal mass ejections, the most massive and destructive explosions from the sun.

In a paper published in the journal Science Advances, a team led by Tingyu Gou from the University of Science and Technology of China was able to clearly observe the onset and evolution of a major solar eruption for the first time.

From a distance the sun seems benevolent and life-giving, but on closer inspection it is seething with powerful fury. Its outer layer - the corona - is a hot and wildly energetic place that constantly sends out streams of charged particles in great gusts of solar wind.

It also emits localised flashes known as flares, as well as enormous explosions of billions of tons of magnetised plasma called coronal mass ejections (CMEs).

These eruptions could potentially have a big effect on Earth. CMEs can damage satellite electronics, kill astronauts on space walks, and cause magnetic storms that can disrupt electricity grids.

Snowflake

Michael Behe: Lessons from polar bear studies on how Darwinism devolves

polar bear
© Sean Kilpatrick/The Canadian PressA polar bear eats a piece of whale meat as it walks along the shore of Hudson Bay near Churchill, Man.
This is the first in a series of posts responding to the extended critique of Darwin Devolves by Richard Lenski at his blog, Telliamed Revisited. Professor Lenski is perhaps the most qualified scientist in the world to analyze the arguments of the book. He is the Hannah Distinguished Professor of Microbial Ecology at Michigan State University, a MacArthur ("Genius Award") Fellow, and a member of the National Academy of Sciences with hundreds of publications, who also has a strong interest in the history and philosophy of science. His own laboratory evolution work is a central focus of the book. I am very grateful to Professor Lenski for taking time to assess Darwin Devolves. His comments will allow interested readers to quickly gauge the relative strength of arguments against the book's thesis.

Although it was not the topic of his first post, I will begin with Lenski's discussion of the example with which I open my book - the polar bear genome - because it illustrates some principles that will be useful going forward. For readers who don't have time to read to the end, here are a couple of take-home lessons:
  • Experimental evidence strongly supports my conclusion (disputed without good reason by Lenski and others) that highly selected mutations in the polar bear genome work by breaking or blunting pre-existing functions.
  • A "function" of a protein is a lower-level molecular feature or activity, such as being a gear or a tether; it should not be confounded with higher-level phenotypic effects, such as "lowers cholesterol" or "makes the organism happy." Ignoring the distinction leads to much confusion.

Sheeple

Doctors knock out sheep to discover anesthesia's dark side

Sheep Surgery
© Carla Gottgens/BloombergSurgery on a sheep during an anesthetics trial at the Florey Institute.
Beneath green surgical sheets and a tangle of tubes, a healthy young ewe is undergoing a heart-lung bypass procedure to help answer one of several urgent questions about a pillar of modern medicine: anesthesia.

Almost two centuries after anesthetics revolutionized surgery, a growing body of research is pointing to disturbing side effects that range from delirium to cancer-proliferating immune suppression. Researchers knocked out the sheep last month at the University of Melbourne to try to understand why common open-heart procedures lead to acute kidney injury in up to a third of patients -- part of a broader effort to study the impact of anesthesia on the immune system, brain and other major organs.

Comment: It's rather amazing, given how common anesthesia is, and how widely its used, how little we actually know about it. It's a vital part of health care, yet it seems in many ways that anesthetizing people is shooting in the dark.

See also:


Comet

Colossal asteroid will approach Earth on Friday, but we'll be fine

Giant asteroid
NASA is always keeping an eye on space rocks that get anywhere near Earth, and 2019 has been a relatively calm year in terms of close passes. A recently discovered asteroid is going to make a not-super-close pass of Earth later this week, and while it doesn't pose much of a threat to our planet it's worth mentioning simply because of its size.

The rock, known as 2019 DN, is slated to arrive at its closest point to Earth this coming Friday, March 8th. At its nearest distance the asteroid will still be around 13 lunar distances away. One lunar distance is equal to the space between the Earth and our Moon, so it's clear the asteroid has little chance of disrupting Earth during its flyby, and that's a very good thing considering its size.

Meteor

6th mass extinction and the 'Shiva hypothesis'

Imapct Event
© Live Science
A total of five mass extinctions occurred during the last 500 million history of the planet earth, when more than 75 per cent of existing life forms had gone extinct. Various causes have been ascribed for each of the five mass extinctions.

The most recent, 5th mass extinction took place about 66 million years ago, when a huge meteorite with a radius of about 10 km crashed on the earth and made a crater with 180 km diameter and 20 km deep in the Yucatan village, Chicxulubin Mexico. The impact created a doomsday scenario.

Superheated dust particles and steam filled the sky preventing sunlight to reach earth for decades killing plant life as they could not carry out photosynthesis. Many volcanoes around the earth became active and spewed lava. There were super-tsunamis drowning land animals and plants. The atmosphere of earth became unsuitable to support most of the existing life forms, leading to the extinction of dinosaurs.

Can the 6th mass extinction occur in a similar manner and all of us would disappear before we figure out what hit us? Michael Rampino and Bruce Haggerty (1984) proposed the 'Shiva hypothesis' (named after Lord Shiva, the Hindu God of destruction) based on an earlier paper of Napier and Clube (1979). According to this hypothesis, the earth experiences large impact events with comets every 30 million years when solar system crosses the plane of Milky Way galaxy. This causes gravitational disturbances in the cloud of comets (Oort cloud) surrounding the solar system and sends some of them hurling towards the inner solar system. These may be propelled to collide with the earth by the 'sling shot' gravitational action of Jupiter (NASA's Voyager-1 and 2 used this effect to escape Sun's gravity).

Modelling studies suggest that an object of 1 km size, depending upon its speed and angle of approach is enough to wipe out the humanity according to Rampino, who gave the 'Shiva hypothesis.' This could throw up enough pulverised rock to block the sun for months. The debris falling back on earth would cause wild fires increasing the surface temperature and killing everything living to death. The earth will then go through a process of cooling and a prolonged winter possibly creating new forms of life millions of years later.

Fireball 5

Asteroid much harder to destroy than previously thought

Impact Event
© MARK GARLICK/SCIENCE PHOTO LIBRARY/Getty ImagesPast modelling for the effect of asteroid collisions has underestimated the force needed to bring about total destruction.
Asteroids are much harder to destroy than previously thought, new modelling shows.

The research, published in the journal Icarus, shows that an asteroid damaged in a collision - by another asteroid, for instance, or a nuclear missile fired at it in the blind hope that doing so will prevent it from smacking into the planet with catastrophic consequences - will substantially reconstruct itself because of the strong gravitational pull of its still-intact core.

The modelling, funded by NASA, substantially updates and contradicts earlier research that showed that a collision between a small asteroid and a large one would completely demolish the latter, the destruction facilitated by the rapid transit of cracks right through it.

The new study, conducted by Charles El Mir and KT Ramesh, of Johns Hopkins University, US, and Derek Richardson, of the University of Maryland, US, applies more fine-grain analysis and arrives at a distinctly different conclusion.

At issue, fundamentally, is the way rocks react to energetic impacts. This process is well understood at what can be called "laboratory scale", wherein real-world and simulated experiments use rocks roughly the size of a human fist.

But asteroids of a magnitude big enough to worry NASA scientists - or tempt would-be space-miners - are considerably larger than that. They might, indeed, be roughly the size of Berlin.

Info

Yale researchers explain the over-tilting exoplanets

Tilting Exoplanets
© Illustration: NASA/JPL-Caltech, Sarah MillhollandYale researchers have discovered a surprising link between the tilting of exoplanets and their orbit in space. The discovery may help explain a long-standing puzzle about exoplanetary orbital architectures.
For almost a decade, astronomers have tried to explain why so many pairs of planets outside our solar system have an odd configuration - their orbits seem to have been pushed apart by a powerful unknown mechanism. Yale researchers say they've found a possible answer, and it implies that the planets' poles are majorly tilted.

The finding could have a big impact on how researchers estimate the structure, climate, and habitability of exoplanets as they try to identify planets that are similar to Earth. The research appears in the March 4 online edition of the journal Nature Astronomy.

NASA's Kepler mission revealed that about 30% of stars similar to our Sun harbor "Super-Earths." Their sizes are somewhere between that of Earth and Neptune, they have nearly circular and coplanar orbits, and it takes them fewer than 100 days to go around their star. Yet curiously, a great number of these planets exist in pairs with orbits that lie just outside natural points of stability.

That's where obliquity - the amount of tilting between a planet's axis and its orbit - comes in, according to Yale astronomers Sarah Millholland and Gregory Laughlin.

Fireball 2

Two previously unknown massive impact craters discovered

Impact Crater
© A. CAVOSIEHiding in plain sight: Morgan Cox (right) collecting breccia samples at the Yallalie impact site.
Researchers have discovered two previously unknown massive craters on Earth, the most recent estimated to have been produced by an impact only 800,000 years ago.

The craters - one in Western Australia and the other in Nicaragua - are revealed in a pair of papers published in the journal Meteoritics and Planetary Science.

In one sense, the Australian crater, in a location known as Yallalie, about 200 kilometres north of the state capital, Perth, has long been hiding in plain sight.

Buried deep beneath the surface, it was first tentatively identified as an impact site in 1992, after its discovery two years earlier during oil drilling exploration.

Subsequent studies of the 12-kilometre-wide circular formation, which also features a raised central structure three kilometres wide, identified it as the result of several meteorite impacts.

Info

Researchers detect giant cosmic bubbles emitting shockwaves through galaxy

NGC 3079 Galaxy
© X-ray: NASA/CXC/University of Michigan/J-T Li et al.; Optical: NASA/STScIThe galaxy NGC 3079, located 67 million light-years from Earth, appears to be blowing two enormous gas bubbles near its galactic center. This combined X-ray and optical light image reveals the superbubbles in their gassy glory.
Astronomers have discovered a distant galaxy that's giddily blowing bubbles like a toddler with a glass of chocolate milk. Unlike milk bubbles, however, these two huge galactic balloons are filled with gas, stretch a few thousand light-years across and appear to be crackling with charged particles 100 times more energetic than any found on Earth.

Using data from the Hubble Space Telescope and NASA's Chandra X-Ray Observatory, researchers detected the bubbles jiggling near the center of a galaxy named NGC 3079, located about 67 million light-years away from Earth. Bubbles like these are known as "superbubbles" because, well, they're supersized. According to the team's study in the Feb. 28 issue of The Astrophysical Journal, one of the newly discovered bubbles measures 4,900 light-years across, and the other measures 3,600 light-years across. (For comparison, the diameter of Neptune's orbit around the sun is about 5.6 billion miles, or 9 billion kilometers - one-thousandth of one light-year.)

Superbubbles form when powerful shock waves shove the gases released by stars far into space, leaving a bubble-shaped cavity behind. Scientists still don't fully understand how these massive gas cavities form.