Was Earth’s Climate Affected by Interstellar Clouds?

About two million years ago, the Solar System may have passed through a dense cloud of hydrogen and radioactive material. It compressed the heliosphere, the protective cocoon the Sun provides for Earth and the other planets. It's shown here as the dark gray bubble over the backdrop of interstellar space. This could have exposed Earth to high levels of radiation and influenced the climate, and possible human evolution. Photo courtesy of Opher, et al., Nature Astronomy

Scientists scour the Earth and the sky for clues to our planet’s climate history. Powerful and sustained volcanic eruptions can alter the climate for long periods of time, and the Sun’s output can shift Earth’s climate over millions of years.

But what about interstellar hydrogen clouds? Can these regions of gas and dust change Earth’s climate when the planet encounters them?

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Webb Sees Asteroids Collide in Another Star System

Asteroid collision: CREDIT:NASA/LYNETTE COOK

The James Webb Space Telescope (JWST) continues to make amazing discoveries. This time in the constellation of Pictor where, in the Beta Pictoris system a massive collision of asteroids. The system is young and only just beginning its evolutionary journey with planets only now starting to form. Just recently, observations from JWST have shown significant energy changes emitted by dust grains in the system compared to observations made 20 years ago. Dust production was thought to be ongoing but the results showed the data captured 20 years ago may have been a one-off event that has since faded suggesting perhaps, an asteroid strike!

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If Gravity Can Exist Without Mass, That Could Explain Dark Matter

Researchers are making progress mapping dark matter, but they don't know what it is. This is a 3D density map of dark matter in the local universe, with the Milky Way marked by an X. Dots are galaxies, and the arrows indicate the directions of motion derived from the reconstructed gravitational potential of dark matter. Image Credit: Hong et al., doi: 10.3847/1538-4357/abf040.

Dark Matter is Nature’s poltergeist. We can see its effects, but we can’t see it, and we don’t know what it is. It’s as if Nature is playing tricks on us, hiding most of its mass and confounding our efforts to determine what it is.

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Landing on Pluto May Only Be A Hop Skip and Jump Away

There are plenty of crazy ideas for missions in the space exploration community. Some are just better funded than others. One of the early pathways to funding the crazy ideas is NASA’s Institute for Advanced Concepts. In 2017 and again in 2021, it funded a mission study of what most space enthusiasts would consider only a modestly ambitious goal but what those outside the community might consider outlandish—landing on Pluto.

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The Milky Way’s Last Merger Event Was More Recent Than Thought

Our home galaxy as seen by the European Space Agency’s Gaia satellite. Image Credit: ESA/Gaia/DPAC

The Milky Way is only as massive as it is because of collisions and mergers with other galaxies. This is a messy process, and we see the same thing happening with other galaxies throughout the Universe. Currently, we see the Milky Way nibbling at its two satellite galaxies, the Large and Small Magellanic Clouds. Their fate is likely sealed, and they’ll be absorbed into our galaxy.

Researchers thought the last major merger occurred in the Milky Way’s distant past, between 8 and 11 billion years ago. But new research amplifies the idea that it was much more recent: less than 3 billion years ago.

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Instead of Losing its Atmosphere, an Exoplanet Puffed Up and Held Onto it

Artist's impression of the "hot Neptune" Phoenix orbiting its red giant star. Credit: Credit: Roberto Molar Candanosa/JHU

To date, astronomers have confirmed the existence of 5638 extrasolar planets in 4,199 star systems. In the process, scientists have found many worlds that have defied expectations. This is certainly the case regarding “hot Neptunes,” planets that are similar to the “ice giants” of the outer Solar System but orbit much closer to their stars. But when a Johns Hopkins University-led team of astronomers discovered TIC365102760 b (aka. Pheonix), they observed something entirely unexpected: a Neptune-sized planet that retained its atmosphere by puffing up.

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Carbon is Surprisingly Abundant in an Early Galaxy

Deep field image from JWST Credit: NASA, ESA, CSA, STScI, Brant Robertson (UC Santa Cruz), Ben Johnson (CfA), Sandro Tacchella (Cambridge), Phill Cargile (CfA)

The James Webb Space Telescope (JWST) has once again found evidence that the early universe was a far more complex place than we thought. This time, it has detected the signature of carbon atoms present in a galaxy that formed just 350 million years after the Big Bang – one of the earliest galaxies ever observed.

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Euclid is Finding Free Floating Planets in Orion Too

There are likely millions of “rogue” or free-floating planets (FFPs) spread through the galaxy. These planets, which aren’t big enough to become stars but also aren’t beholden to a star’s gravity, are some of the hardest objects for astronomers to spot, as they don’t give off their own light, and can only be seen when they cross in front of something that does give off its own light. Enter Euclid, a space telescope that launched last year. Its primary mission is to observe the universe’s history, but a new paper describes an exciting side project – finding FFPs in Orion.

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Where Did Venus's Water Go?

HCO+ molecules reacting in the atmosphere of Venus. Credit: Aurore Simonnet/LASP/CU Boulder
In Venus' upper atmosphere, hydrogen atoms, orange, whiz into space, leaving behind carbon monoxide molecules, blue and purple. (Credit: Aurore Simonnet/LASP/CU Boulder)

It should not be surprising that Venus is dry. It is famous for its hellish conditions, with dense sulphurous clouds, rains of acid, atmospheric pressures comparable to a 900 meter deep lake, and a surface temperature high enough to melt lead. But it’s lack of water is not just a lack of rain and oceans: there’s no ice or water vapour either. Like Earth, Venus is found within our Solar System’s goldilocks zone, so it would have had plenty of water when it was first formed. So where did all of Venus’s water go?

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