Thursday, July 3, 2025

If Dark Energy is Decreasing, is the Big Crunch Back on the Menu?

Dark Energy Spectroscopic Instrument. Credit: DOE

Astronomers once wondered if the Universe might one day collapse in on itself in a Big Crunch, but the discovery of dark energy suggested that the expansion of the Universe would accelerate, removing that possibility. New data from the Dark Energy Spectroscopic Instrument suggests that dark energy might be changing in strength over time, maybe even going negative. If that result holds, are we due for a Big Crunch? And how long would it take?



High-Speed Gas Clouds Fuel Star Formation in Depleted Galaxies

M83 is a grand design spiral galaxy also known as the Southern Pinwheel Galaxy. New research found clouds of gas moving strangely in the galaxy. These clouds could have come from an external source and are triggering more star formation. Image Credit: NASA, ESA and the Hubble Heritage Team (STScI/AURA); Acknowledgment: W. Blair (STScI/Johns Hopkins University) and R. O’Connell (University of Virginia)

How do galaxies like ours continue producing stars long after they should have used up their star-forming gas. Somehow, an external gas source must find its way into the galaxy. New research has found evidence of gas clouds that found their way into a spiral galaxy, likely fueling continued star formation.



A Star Detonated as a Supernova... Twice

VLT image of a double-detonation supernova. Credit: ESO

The beautiful supernova remnant looks a little different from other examples of stars that detonated in the past. And it should, because according to astronomers, the star that met its end exploded twice. It was a white dwarf in its former life, pulling material from a binary companion, creating the perfect conditions for a Type 1a supernova. It accumulated a blanket of helium, which exploded first, triggering a second detonation at the core of the star.



Peering Into a Starburst Galaxy With the JWST

This is the NASA/ESA/CSA James Webb Space Telescope Picture of the Month. The powerful infrared space telescope captured this image of the Cigar Galaxy (M82) with its Mid-Infrared Instrument (MIRI). Rather than reveal the presence of the galaxy's stars, it shows the infrared emissions from warm dust and clouds of polycyclic aromatic hydrocarbons (PAHs). Image Credit: ESA/Webb, NASA & CSA, A. Bolatto. CC BY 4.0 INT

Astronomers used the JWST to examine M82, a nearby starburst galaxy. M82 is forming stars at a prodigious rate due to its interactions with its neighbour, M81. It produces thousands of solar masses of stars per year, much more than the Milky Way.



Wednesday, July 2, 2025

Weather Satellites Can Even Study the Weather Over on Venus

Venus as seen by Himawari satellites. A photo with magnified sections to show just how small Venus is in the field of view of the observation satellites. Despite this limitation, researchers can still gather useful data. ©2025 Nishiyama et al. CC-BY-ND

A pair of Japanese weather satellites took a break from monitoring Earth weather to sneak a peek at Planet Venus. Despite the fact that it's relatively tiny, and millions of kilometers away, they were able to detect changes in Venus' cloud-top temperatures and see patterns and structure in its upper atmosphere. There are long-term trends on Venus that these long-lasting satellites will be able to study, beyond the timeframe of a shorter mission.



Tianwen-2 Looks Back at the Earth

Earth, seen by Tianwen-2. Credit: CNSA

China's asteroid probe turned its cameras back towards the Earth and Moon, capturing an image of our home planet on May 30, 2025. The image was taken when the spacecraft was about 590,000 km away, speeding towards asteroid 2016HO3, where it will retrieve a sample and bring it back to Earth before carrying on to main-belt comet 311P. The spacecraft has been in flight for 33 days and is now over 12 million kilometers from Earth.



In the Search for Earth-like Worlds, We Should Probably Focus on Red Dwarfs

In this artist's illustration, several small exoplanets orbit an M-dwarf (red dwarf) star. New research suggests that these low-mass stars often host Earth-like exoplanets. Image Credit: NASA/JPL-Caltech/MSSS.

According to the latest studies led by Heidelberg University astronomers, low-mass stars quite often host Earth-like planets. Data collected as part of the CARMENES project were the basis of this finding. By analyzing the data, an international research team succeeded in identifying four new exoplanets and determining their properties.