The Madness from the Sea

Paleontologists have discovered a real-life version of one of the most feared monsters in fiction… only smaller. And probably not an eldritch horror from beyond the stars.

An international team of researchers unveiled the fossilized remains of an ancient relative of the sea cucumber. It had 45 tentacles and lurked at the bottom of the seas some 430 million years ago.

They have dubbed it Sollasina cthulhu, after the tentacled Great Old One of H.P. Lovecraft’s tales, a study published in the journal Proceedings of the Royal Society B said.

Unlike the massive Cthulhu of fiction, the creature unveiled by scientists this week was quite tiny, with the fossil measuring about an inch across. However, the researchers said those 45 “tube feet” extended out in every direction and would make it seem much larger as it sat on the ocean floor, waiting and dreaming…

Sleep well…

Despite its diminutive size, the creature still manages to pack a lot of nightmare fuel. Those 45 tentacles were used to snatch up food, creep along the ocean floor, and scare off predators.

Oh, and those “tubes” also had their own armor.

The tube feet of living echinoderms are naked, but in the ophiocistioids they were plated, strongly suggesting that ophiocistioids diverged from the line leading to modern sea cucumbers.

The First Pic of a Black Hole

Scientists from a global collaboration of telescopes announced Wednesday that they have captured the first-ever photo of a black hole.

The collaboration, called the Event Horizon Telescope, is a global network of eight telescopes that has been working for two years to capture the first image of a black hole, by combining data from the eight telescopes and “creating a virtual Earth-sized telescope.”

“We have seen what we thought was unseeable,” Shep Doeleman, the director of the EHT, said during a news conference Wednesday.

In 2017, the group embarked on a week long observation spanning telescopes in four continents, capturing data from two black holes: one in Sagittarius A*, located at the center of the Milky Way galaxy, and the other in the Messier 87 galaxy, in the constellation Virgo.

MIT’s Katie Bouman with the hard drives used to store the black hole image data. 

The Fate of the Earth

If it weren’t for the sun constantly showering us with energy, there would be no life on Earth. But eventually the sun will run out of fuel, expand into a red giant and finally collapse into faint, white dwarf. What will happen to us and the other planets in the solar system when the sun dies? It’s not entirely clear.

Scientists think that they have spotted the possible core remnant of a planet orbiting the white dwarf SDSSJ122859.93+104032.9, residing some 410 light years away. The results, published in Science, offer important clues about the fate of the planets in our solar system.

The planetary fragment produced a stream of gas that could be detected by spectrometers. Researchers spotted it orbiting the star by looking at how its spectrum shifted in color as the body moved towards and away from Earth. This change in color is called a doppler shift, which is essentially a stretching or squashing of waves because of motion. It is similar to the pitch of the sound of an ambulance being higher when it is heading towards you, and lower when it is moving away.

The object completed one passage around its host star in just over two hours, orbiting at a distance that is smaller than the radius of the sun in a disc of gas and dust.

The discovery is surprising, since scientists didn’t think anything could survive so close to a white dwarf. A white dwarf is only about the size of the Earth but it contains around 60-70% of the sun’s mass, making it extremely dense. If a body orbits too close to a white dwarf, its immense gravity will rip it apart. This was likely the fate of the material that formed the disc around it.

So how did this object survive without getting ripped apart? It would have to either be very dense itself or have some amount of internal strength holding it together. Scientists calculated that it has a maximum diameter of 720km, which is the size of a small minor planet. The dwarf planet Ceres in our solar system has a diameter of 946km by comparison.

The origin of this object remains a mystery. One possibility is that this is the core of a minor planet that was pushed close to the white dwarf by a larger planet further out in the remnant planetary system, like a Jupiter. As the minor planet passed close to the white dwarf, its crust and mantle layers would have been ripped away.

All that would be left of the planet would be its dense, iron-dominated core. This kind of object is quite common, with one famous resident in our own solar system: the asteroid 16-Psyche.

Systems such as the one just discovered can help us understand the future of our own planetary system. In about five billion years, the sun will start to expand into a red giant. At this point, it will engulf Mercury, Venus and most likely Earth, unless we manage to move our planet into a wider orbit, which should be possible in theory. However, Mars, the asteroid belt and the rest of the solar system will survive engulfment and continue orbiting the sun as it then collapses into a white dwarf.

Image result for red giant sun

During this process, planets like Jupiter could also scatter asteroids, comets or even minor planets towards the white dwarf. There they would undergo partial or complete disruption, forming a disc like the one just discovered. It is unlikely that any living organisms on planetary or moon fragments could survive this process. Even if they did, they would struggle to live on in the faint light of a white dwarf.

This is not only the solar system’s fate, but that of practically all known exoplanet systems. In the much much closer future, scientists hope to find more planetary bodies around other white dwarfs. There are six candidate white dwarfs that are orbited by discs made of dust and gas, and researches want to test whether these discs are the “smoking gun” for the presence of minor planets. The more such planets are found, the more that can be learned about what happens to a planetary system as its star dies.

Curiosity Catches Two Eclipses

The cameras on NASA’s Curiosity rover usually look down at the rocks on Mars, divining clues in the minerals of what the planet was like billions of years ago.

Sometimes though, the rover also looks up, and in March it spotted two eclipses (eclipsi?).

Eclipses on Mars are not as total as those on Earth where the moon completely blots out the sun. The two moons of Mars are tiny. Phobos is 7 miles wide while Deimos is even tinier, just 1.5 miles in diameter. They only partially block the sun when they pass in front of it.

The camera on Curiosity’s mast is equipped with solar filters that allow it to look directly at the sun and photograph eclipses. On March 17, Curiosity observed Demios eclipsing the sun. Nine days later, it also spotted Phobos passing in front.

The observations by Curiosity, and by earlier NASA Mars rovers, Spirit and Opportunity, enable more precise pinpointing of the moons’ orbits, which are jostled around by the gravity of Mars, Jupiter, and even each other.

Although Phobos and Deimos are small, the details of their formation are of considerable scientific interest. Japan’s space agency plans to send a spacecraft to the two moons within the next decade. The Mars Moon Exploration probe, or MMX, will collect samples and return them to Earth for study. A panel of scientific experts recently approved the sample-return phase of the mission.

Passing Gas on Mars

Methane gas is periodically detected in the atmosphere of Mars. This was once considered implausible and perplexing, but it is now widely accepted by planetary scientists. Why the methane is there is still a mystery. It could point to present-day Martian microbes living in the rocks below the surface.

Image result for mars

Scientists working with the ESA’s Mars Express orbiter reported that in the summer of 2013, the spacecraft detected methane within Gale Crater, a 96-mile-wide depression near the Martian equator.

In the same summer of 2013, NASA’s Curiosity rover also measured a marked rise of methane in the air that lasted over two months.

The presence of methane is significant because the gas decays quickly. Calculations indicate that sunlight and chemical reactions in the thin Martian atmosphere would break up the molecules within a few hundred years, so any methane detected must have been created recently.

It could have been created by a geological process known as serpentinization, which requires both heat and liquid water. Or it could be a product of life, specifically methanogens, microbes that release methane as a waste product. Methanogens thrive in places lacking oxygen, such as rocks deep underground and the digestive tracts of animals.

Even if the source of the methane turns out to be geological, the hydrothermal systems that produce the emissions would still be prime locations to search for signs of life.

A newer European Mars spacecraft, the Trace Gas Orbiter, which has a more sophisticated methane detector, has been in orbit since 2017, but no results have been reported as of yet.