Astro/Physics

Fi rstImages of Venus 'Surface

USING THE WIDE-FIELD IMAGER (WISPR) INSTRUMENT, NASA’S PARKER SOLAR PROBE HAS CAPTURED THE FIRST VISIBLE LIGHT IMAGES OF VENUS’S SURFACE FROM SPACE. ALTHOUGH VENUS IS THE THIRD BRIGHTEST OBJECT IN THE SKY, NOT MUCH INFORMATION HAS BEEN UNCOVERED DUE TO ITS DENSE ATMOSPHERE SHROUDING THE SURFACE. HOWEVER, WISPR WAS ABLE TO PEER THROUGH DURING FLYBYS AND CAPTURE IMAGES OF THE NIGHTSIDE OF VENUS IN VISIBLE LIGHT. THESE IMAGES ADDED TO PREVIOUS ONES BY “EXTENDING THE OBSERVATIONS TO RED WAVELENGTHS AT THE EDGE OF WHAT WE CAN SEE. ” THESE FINDINGS WILL EVENTUALLY HELP SCIENTISTS BETTER UNDERSTAND THE GEOLOGY, MINERAL COMPOSITION, AND EVOLUTION OF VENUS, AS WELL AS IF VOLCANISM WAS A FACTOR IN THE CREATION OF ITS THICK ATMOSPHERE. THIS WILL ALLOW SCIENTISTS TO FIND OUT WHAT MADE VENUS INHOSPITABLE TODAY, AND WHETHER IT WAS ONCE A WORLD WHERE LIFE FLOURISHED.

by: Michelle Lei

In the outback of Western Australia, an honors student at Curtin University peers through Australia’s Murchison Widefield Array (MWA) telescope, and spots something strange: a spinning object, well within our galactic backyard, sending out an impossibly strong radio wave every twenty minutes.

Of course, stellar objects turning on and off are not entirely new to the astronomy community; such objects are referred to as ‘transients, ’ which include short-lived supernovae, who disappear after the course of a few months, and rapidly spinning pulsars, which turn on and off in a matter of milliseconds. However, there was something off about this specific case. This object did turned on and off in regular intervals of 20 minutes, an unheard of time-frame.

This description, the team realized, matched the same criteria as a theorized astrophysical object known as an ‘ultra-long period magnetar, ’ a type of slow spinning neutron star. This observed instance of one is significantly brighter than astrophysicists have theorized, apparently converting magnetic energy to radio waves in a far more effective way than any prior observed object.

The MWA director is continuing to focus on observing more of these objects in our night sky, coordinating with other telescopes and astronomers to see if they too can discover if there is a greater, as-of-yet unrevealed population of these objects out there, waiting to be found.

Our moon has loomed above us for millennia, a staple of an earthly night sky. We owe it a great many aspects of our day-to-day (or perhaps, ‘night-to-night’) life; it controls the length of our days, the tides of our oceans, and stabilizes our planet’s spin.

It is as a result of these crucial roles the moon plays in maintaining life on Earth that scientists have begun to conjecture that the presence of a moon may be conducive to habitability on other planets. Our moon is unique in that it’s quite large compared to the size of Earth—its radius is larger than a quarter of our own, an impressive size ratio when compared to that of other moon-planet pairs.

As such, astronomers have delved into examining the formation of moons and developing an understanding of the contributing factors leading to a large moon through the usage of various simulated impacts, akin to those responsible for the creation of our own moon. Our moon was the result of an impact between a proto-Earth and a Mars-sized impactor, creating a partially vaporized disk around the newly fledged Earth that had eventually become the moon we know today.

In the simulations, it was discovered that significantly larger planets—rocky planets larger than six times the mass of Earth and icy planets larger than the Earth’s mass—produced fully-vaporized disks instead, which could not form large moons. This is due to how, in fully vaporized disks, the moonlets present within—liquid building blocks of moons, formed from cooling within the planetary disk—experience enough drag from their vaporous brethren that they are pulled down to the planet’s surface. Meanwhile, in a partially vaporized disk, such gas drag is not nearly as strong.

This research has given searchers for habitable exoplanets a new criterium: planetary masses must be smaller than these identified thresholds if they are to produce similar moons, which may, in turn, hold the key to life. By Adam Santana

Although cyanide is known to be a lethal gas used in chemical warfare, it may have had a great role in the early years of life on Earth, billions of years ago. Chemists at Scripps Research have discovered how cyanide could have spurred metabolic reactions to make carbon-based compounds from carbon dioxide.

According to Ramanarayanan Krishnamurthy, PhD, an associate professor of chemistry at Scripps Research, biochemistry is a big help in understanding the first signs of life on various planets. Since cyanide spurred these early metabolic reactions, that says a lot about how different life could be.

One type of chemical reaction that bacteria today goes through is called the reverse tricarboxylic acid cycle (r-TCA cycle) that processes carbon dioxide and water into chemical compounds that are essential for life. However, today ’ s bacteria ’ s r-TCA cycle is much more evolved than that of early life, utilizing various proteins that didn ’t even exist back then. Instead of using these modern proteins, these bacteria would use metals to spur the chemical reactions vital to life. This only would work under very acidic/hot conditions though, which isn ’t common on Earth at least. Knowing that cyanide was present on early Earth, Krishnamurthy theorized that cyanide could’ ve been one of the metals used in the r-TCA cycle. He and his colleagues used some cyanide in a test tube and experimented with some chemical reactions. It worked, and cyanide successfully was able to spur the transfer of electrons between molecules! Plus, this worked under regular room temperature conditions and at a wide pH range, showing what life was like on early Earth.

Therefore, cyanide simplified the r-TCA cycle and was actually quite simple in comparison to the modern cycle. It’ s interesting how chemistry played a role so early in life on Earth, and this discovery really helped gain insight on what it was like. There is even a possibility that life could evolve from these cyanide driven reactions, according to Krishnamurthy.

Cyanide, and its Role in the Search for Extraterrestrial Life 20

Evolution of Life on Earth Affected by Supermountains

"Giant mountain ranges at least as high as the Himalayas and stretching up to 8,000 kilometres across entire supercontinents played a crucial role in the evolution of early life on Earth, according to a new study by researchers at The Australian National University (ANU). " The formation of these mountains were tracked by the researchers utilizing zircon traces with low content of lutetium which is a mineral and rare earth element combination that can be found in high mountains' roots. It was found from the study that the most giant supermountains were also formed twice, one of which was between 2000 and 1800 million years ago and the other which was formed between 650 and 500 million years ago.

"Both mountain ranges rose during periods of supercontinent formation. " It was said by Ziyi Zhu, the lead author, that these two instances and the two most important evolution periods have links between them. For example, the Nuna Supermountain coincides with the eukaryotes' likely appearence. The Transgondwanan Supermountain coincides with the first large animals' appearance. The erosion of these supermountains provided to the oceans essential nutrients which supercharges "biological cycles and driving evolution to greater complexity. "

Also, the supermountains may have created a boost in oxygen levels. There was almost no oxygen in Earth's early atmosphere. It was thought that there is a correlation between the oxygen levels and the supermountains.