Category Astronomy/Space

Mars’ Surface Shaped by Fast and Furious Floods from Overflowing Craters

Mars outlet crater
Craters and river valleys on the surface of Mars. A breached crater lake and outlet valley are outlined in white. Credit: NASA/GSFC/ JPL ASU

On Earth, river erosion is usually a slow-going process. But on Mars, massive floods from overflowing crater lakes had an outsized role in shaping the Martian surface, carving deep chasms and moving vast amounts of sediment, according to a new study led by researchers at The University of Texas at Austin.

The study, published Sept. 29 in Nature, found that the floods, which probably lasted mere weeks, eroded more than enough sediment to completely fill Lake Superior and Lake Ontario.

“If we think about how sediment was being moved across the landscape on ancient Mars, lake breach floods were a really important process globally,” said lead au...

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What happens to Interstellar Objects Captured By the Solar System?

This figure from the study shows some simulation results. Each blue line is an individual ISO. The top represents the osculating pericenter distance in AUs. The bottom shows inclination in degrees. In their simulations, individual objects don't become distinguishable until after about 100 million years. When a blue line ends, that ISO has left the Solar System. Image Credit: Napier et al 2021.
This figure from the study shows some simulation results. Each blue line is an individual ISO. The top represents the osculating pericenter distance in AUs. The bottom shows inclination in degrees. In their simulations, individual objects don’t become distinguishable until after about 100 million years. When a blue line ends, that ISO has left the Solar System. Image Credit: Napier et al 2021.

Now that we know that interstellar objects (ISOs) visit our solar system, scientists are keen to understand them better. How could they be captured? If they’re captured, what happens to them? How many of them might be in our solar system?

One team of researchers is trying to find answers.

We know of two ISOs for certain: “Oumuamua and comet2I/Borisov...

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Hubble Shows Winds in Jupiter’s Great Red Spot are Speeding up

Like the speed of an advancing race car driver, the winds in the outermost “lane” of Jupiter’s Great Red Spot are accelerating – a discovery only made possible by NASA’s Hubble Space Telescope, which has monitored the planet for more than a decade.

Researchers analyzing Hubble’s regular “storm reports” found that the average wind speed just within the boundaries of the storm, known as a high-speed ring, has increased by up to 8 percent from 2009 to 2020. In contrast, the winds near the red spot’s innermost region are moving significantly more slowly, like someone cruising lazily on a sunny Sunday afternoon.

The massive storm’s crimson-colored clouds spin counterclockwise at speeds that exceed 400 miles per hour – and the vortex is bigger than Earth itself...

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Earth and Venus grew up as Rambunctious Planets

Simulated aftermath of a hit-and-run collisions between the young Earth and  another planetary body
The moon is thought to be the aftermath of a giant impact. According to a new theory, there were two giant impacts in a row, separated by about 1 million years, involving a Mars-sized ‘Theia’ and proto-Earth. In this image, the proposed hit-and-run collision is simulated in 3D, shown about an hour after impact. A cut-away view shows the iron cores. Theia (or most of it) barely escapes, so a follow-on collision is likely.A. Emsenhuber/University of Bern/University of Munich

Using machine learning and simulations of giant impacts, researchers found that the planets residing in the inner solar system were likely born from repeated hit-and-run collisions, challenging conventional models of planet formation.

Planet formation — the process by which neat, round, distinct planets form from ...

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