New Delhi: Data from ISRO’s Mars Orbiter Mission shows that dust storms on the Red Planet causes its upper atmosphere to undergo warming and expansion, which in turn causes some of its gases to escape into outer space.
Planets in the solar system constantly lose their atmospheres to outer space. The rate of this loss depends on the size of a planet and temperature of its upper atmosphere.
Since Mars is a relatively smaller planet compared to the Earth, it is losing its atmosphere at a faster rate. However, ISRO has now found how this loss is altered by the changes in the upper atmospheric temperature on Mars.
Characterising the Martian upper atmosphere is extremely important to understand this loss rate. This was one of the primary goals of the recent missions to Mars such as NASA’s Mars Atmosphere and Volatile Evolution (MAVEN) and ISRO’s Mars Orbiter Mission (MOM).
In the first week of June 2018, a dust storm started growing on Mars, engulfing the whole planet by the first week of July 2018. During this time, India’s Mars orbiter observed the evening side of Mars by diving down to altitudes as low as 155 km.
By analysing the data, scientists found that the upper atmosphere was undergoing warming and expansion as the dust storm slowly engulfed Mars over a month.
The team also inferred that the heating and expansion of global dust storm leads to a part of its atmosphere to quickly reach the exobase altitude at 220 km. Exobase is the outermost region of a planet’s atmosphere.
Any hot gases above the exobase altitude are more likely to move to further higher altitudes and subsequently escape to outer space. The study found that the 2018 global dust storm resulted in enhanced escape of the Martian atmosphere. More on ISRO.
Scientists decode effect of volcanic activity on Jupiter’s moon Io
The Atacama Large Millimeter/submillimeter Array (or ALMA) has for the first time documented the direct effect of volcanic activity on the atmosphere of Jupiter’s moon Io.
Io is the most volcanically active moon in our solar system, hosting over 400 active volcanoes. These volcanoes throw up sulphur gases that give Io its colours when they freeze out on its surface.
The images of Jupiter’s moon Io in radio waves (made with ALMA), and optical light (made with Voyager 1 and Galileo missions) for the first time show plumes of sulphur dioxide in yellow rising up from the volcanoes on Io.
To distinguish between the different processes that give rise to Io’s atmosphere, the team took snapshots of the moon when it passed in and out of Jupiter’s shadow.
Based on the snapshots, they calculated that active volcanoes directly produce 30-50 per cent of Io’s atmosphere.
When Io passes into Jupiter’s shadow, and is out of direct sunlight, it becomes too cold for sulphur dioxide gas, which condenses onto Io’s surface. During that time only volcanically-sourced sulphur dioxide is visible. This allows researchers to infer exactly how much of the atmosphere is impacted by volcanic activity.
The ALMA images also showed a third gas coming out of volcanoes: potassium chloride. More on CNN.
Researchers find evidence of ‘lost’ tectonic plate
Scientists in the US believed that they have found a long lost piece of puzzle in the Earth’s tectonic plates.
The existence of a tectonic plate called Resurrection has been a topic of debate among geologists. This is because while some argue that it never existed, others say it went into the Earth’s mantle somewhere in the Pacific Margin between 40 and 60 million years ago.
Using existing mantle tomography — which is similar to taking a CT scan of the Earth’s interior — the team found direct evidence that the Resurrection plate existed.
The reconstructed boundaries of this ancient plate match well with the ancient volcanic belts in Washington State and Alaska.
Detailed study of tectonic plates is important because it helps geologists better predict volcanic hazards, as well as find mineral and hydrocarbon deposits. More on LiveScience.
2 dinosaurs, ancient ancestors of birds, didn’t know how to fly
Scientists have found that two small dinosaurs — living about 160 million years ago — had bat-like wings, but were unable to learn to fly.
They could only manage to glide clumsily between trees. This became a significant disadvantage for the two species, because they were unable to compete with other tree-dwelling dinosaurs and early birds.
As a result, they went extinct after just a few million years. The findings show evolution of wings took several different paths before modern birds came to life.
The two species, known as Yi and Ambopteryx, weighed less than two pounds. They are unusual examples of theropod dinosaurs, which are ancient ancestors of birds.
Most theropods were ground-loving carnivores, but Yi and Ambopteryx lived in trees and survived on a diet of insects, seeds, and other plants.
The team scanned fossils with a technique that uses laser to pick up soft-tissue details that can’t be seen with standard white light. Then they used mathematical models to predict how the dinosaurs may have flown.
While gliding is not an efficient form of flight, since it can only be done if the animal has already climbed to a high point, it did help Yi and Ambopteryx stay out of danger.
Here’s what makes the humble beetle nearly indestructible
Scientists have found what makes the beetle’s exoskeleton one of the toughest, most crush-resistant structures known to exist in the biological world.
The beetle’s exterior is so strong that it can’t be crushed even if run over by a car. It can withstand a force of about 39,000 times its body weight. That is equivalent to a 200-pound man (approximately 90 kg) enduring the crushing weight of 7.8 million pounds (approximately 35 lakh kg).
In a new study, scientists have revealed the material components — and their nano-scale blueprints — that make the organism so indestructible.
The findings may also help engineers design sturdy, indestructible structures.
In its desert habitat in Southwest North America, the beetle can be found under rocks and in trees, squeezed between the bark and the trunk — another reason it needs to have a durable exterior.
The bug’s secret lies in its exoskeleton, specifically, its elytra. In beetles, elytra are the forewing blades that open and close to safeguard the flight wings.The ironclad’s elytra have evolved to become a solid, protective shield.
The elytra consists of layers of chitin, a fibrous material, and a protein matrix. The beetle’s outer layer has a significantly higher concentration of protein which enhances the toughness of the elytra.
A cross section of where the two halves of the beetle’s elytra meet looks like interlocking pieces of a jigsaw puzzle. The outside surfaces of these blades feature arrays of rodlike elements that scientists believe act as frictional pads, providing resistance to slippage. More on Scientific American.