‘Countless’ interstellar objects found at edge of solar system & how bacteria make electricity

ScientiFix, our weekly feature, offers you a summary of the top global science stories of the week, with links to their sources.

A representative image of the distance of the planets in the solar system from the Oort cloud | Commons

New Delhi: Scientists have found that the Oort cloud, a spherical layer of icy objects at the edge of the solar system, may be home to countless interstellar objects belonging to our solar system.

In 2019, astronomers spotted a rogue comet from another star system in our solar system. Named Borisov, the icy snowball was the first and only interstellar comet ever detected by humans.

But the new study suggests that these interstellar visitors are more common in the solar system than we think. In fact, they may outnumber the objects within the solar system.

Before the detection of the first interstellar comet, theory on the formation of planetary systems suggested that there should be fewer visitors than permanent residents.

The latest study, which makes calculations using conclusions drawn from Borisov, suggests that interstellar visitors prevail over objects that are native to the solar system.

The Oort Cloud spans a region some 200 billion to 10 trillion miles away from the Sun, and unlike stars, objects in the Oort Cloud don’t produce their own light. Those two factors make debris in the outer solar system hard to see.

Observations with next-generation technology may help confirm the team’s results. The launch of the Vera C. Rubin Observatory in Chile, slated for 2022 for example, will possibly help detect many more visitors like Borisov. Read More.

Trove of ancient tools made of elephant bones found in Italy

Scientists have discovered a trove of tools made out of elephant bones in Italy, dating back to roughly 400,000 years, some of which wouldn’t become objects of common use for another 100,000 years.

Although the use of bone tools were common at the time, it is the way they had been crafted that impressed the scientists.

The researchers recovered the tools from a site called Castel di Guido not far from modern-day Rome. Hundreds of thousands of years ago, it had a stream that attracted thirsty 13-foot-tall creatures called straight-tusked elephants.

The scientists believe that elephants would occasionally die of natural causes near the stream, and the ancient humans made good use of the remains.

These Stone Age residents produced tools using a systematic, standardised approach, a bit like a single individual working on a primitive assembly line.

The team believes that humans at the time were breaking the long bones of the elephants in a standardised manner and producing standardised pieces to make bone tools. Such kind of aptitude didn’t become common until much later.

Around 400,000 years ago, Neanderthals were just beginning to emerge in Europe. The researchers suspect that these ancient humans (whose tools have now been found) were actually Neanderthals.

Some of the tools were pointed and could have been used to cut meat. Others were wedges that may have been helpful for splitting heavy elephant femurs and other long bones.

The team also discovered a single artifact carved from a wild cattle bone which resembles what archaeologists call a “lissoir,” or a smoother, a type of tool that ancient humans used to treat leather. But such tools didn’t become common until about 300,000 years ago. Read More. 

Scientists decode how some bacteria produce electricity

Scientists have identified a hair-like protein hidden inside bacteria that serves as a sort of on-off switch for nature’s “electric grid”, which is a global web of bacteria-generated nanowires that permeates all oxygen-less soil and deep ocean beds.

Scientists hope to use this natural electrical grid to generate electricity, new biofuels and even self-healing electronic components.

Almost all living things breathe oxygen to get rid of excess electrons when converting nutrients into energy. Without access to oxygen, however, soil bacteria living deep under oceans or buried underground over billions of years use tiny protein filaments called nanowires to get rid of excess electrons. Moving electrons is what creates electricity

However, how these soil bacteria exhale electricity has remained a mystery. Since 2005, scientists had thought that the nanowires are made up of a protein called “pili” that many bacteria show on their surface.

However, scientists found that these nanowires are made of entirely different proteins.

For the new study, researchers used cryo-electron microscopy to reveal that this pili structure is made up of two proteins and instead of serving as nanowires themselves, pili remain hidden inside the bacteria and act like pistons, thrusting the nanowires into the environment. Read More.

Continents may merge into supercontinent in 250 million years

Using computer models to travel forward in time, researchers have predicted two possible scenarios for the evolution of the Earth, 250 million years later. Both these involve all the continents moving together to form the next supercontinent.

The first scenario predicts the formation of the supercontinent of Aurica, a low latitude supercontinent. Aurica will have very little snow or ice and an average temperature of around 20 degree Celsius.

The second possibility is that a super continent called Amasia forms at a high latitude, along with a smaller Antarctic subcontinent about 200 million years from now. Amasia will be a continent dominated by snowfall and ice-sheets.

This bright, white supercontinent will reflect back more of the sun’s heat and have a climate similar to the Earth’s last ice age.

The researchers said that these predictions of how the Earth might evolve may help look for exoplanets (planets outside the solar system) that may have once hosted life. Read More.

Russian part of ISS at risk of irreparable failures

A Russian space official this week raised concerns about the deteriorating state of Russia’s segment of the International Space Station, warning that the out-of-date hardware could lead to “irreparable failures”.

According to Vladimir Solovyov, chief engineer of the Energia rocket and space corporation, 80 per cent of the inflight systems on Russia’s segment have reached the end of their service period.

Energia — a manufacturer of spacecraft and space station components — is the leading developer of Russia’s section of the ISS, a joint venture with the United States, Canada, Japan and the European Space Agency.

Russia had previously indicated that it plans to leave the ISS after 2025 and launch its own orbital station. The official also said that small cracks had been discovered on Russia’s Zarya cargo module. Launched in 1998, it is one of the oldest modules of the ISS.

Also, in July the entire ISS had briefly tilted out of orbit after the thrusters of a new Russian module reignited several hours after docking. Read More.

(Edited by Poulomi Banerjee)