Is alien life purple? When we look at Earth from space, the color green means life. It represents trees, grass, crops and everything that grows with the help of chlorophyll. Chlorophyll is a pigment found in nearly all plants that use photosynthesis to absorb energy from the sun and turn light into fuel. Chlorophyll also gives plants their green color. But in some environments on Earth without sunlight or oxygen, life uses infrared radiation for energy. And many of these bacteria are purple. What if life on other worlds uses infrared radiation instead of sunlight? According to a press release ..read more

EarthSky’s Deborah Byrd created this 1-minute video summary for you on Gaia BH3! The most massive stellar black hole in the Milky Way is now Gaia BH3. It has a mass 33 times that of our sun. Gaia BH3 is located 2,000 light-years away in the constellation Aquila, making it the 2nd-closest known black hole to Earth. The discovery challenges previous theories, suggesting that high-mass black holes may form from metal-poor stars, supported by Gaia’s observation of a metal-poor companion star to Gaia BH3. EarthSky needs YOUR help to keep going. Your support, comments, photos, suggestions for sto ..read more

EarthSky’s Deborah Byrd created this 1-minute video summary for you. How Pluto got its heart! New insights on the origin of Pluto’s heart-shaped feature came from scientists using numerical simulations. They said a cataclysmic collision created the western lobe of Pluto’s heart, called Sputnik Planitia. The impacting body was over 400 miles in diameter. It altered Pluto’s inner structure. These scientists now doubt Pluto has a subsurface ocean. Their simulations suggest the heart’s formation and position on Pluto can explained by a local mass excess from the impact, rather than ocean dynamic ..read more

Here’s the image of the large asteroid – 2013 NK4 – that safely passed Earth on Monday, April 15, 2024. The Goldstone Radar in California acquired this image on April 13. Image via NASA/JPL-Caltech.Update! Image of asteroid 2013 NK4 NASA astronomers were able to obtain radar images of the large asteroid that passed Earth safely on Monday, April 15, 2024. They captured an image of the asteroid – named 2013 NK4 – using the Goldstone Radar in California on April 13. NASA said: Radar narrow echoes probably establish that 2013 NK4 rotates very slowly, and the shape is bifurcated. These observatio ..read more

View larger. | Here’s the Mars rock known as Bunsen Peak. The white hole on the left is the drill hole, left by NASA’s Perseverance rover. The white hole on the right is where the rover first abraded or rubbed the rock. This rock is rich in carbonate and silica. Those are clues it was once drenched in water. Mission scientists said it likely originated on an ancient lakeshore beach. If so, it’d be ideal for preserving traces of microscopic Martian life. Image via NASA/ JPL-Caltech/ ASU/ MSSS. NASA’s Perseverance rover has sampled a Mars rock called Bunsen Peak. The rock is of high interest to ..read more

New features detected by Webb are superimposed in orange on HL Tauri and its protoplanetary disk, located 357 light-years from Earth. The image reveals material in the envelope immediately surrounding the young star, apart from the larger disk. There is also an opening formed by material flowing out of the system. HL Tauri was one of the targets imaged by NASA’s Webb Space Telescope in its search for baby planets in young planetary systems. Image via Camryn Mullin et al./ The Astronomical Journal/ University of Arizona (CC BY 4.0). The James Webb Space Telescope has now acquired images of thr ..read more

View larger. | False-color view of the water vapor plumes on Enceladus, which Cassini took on November 27, 2005. The colors are enhanced to help show individual plumes. Now, a new study of Cassini data has found evidence for sub-micrometer particles in the plumes that are the same size as some bacterial cells in hydrothermal vents in Earth’s oceans. There is also evidence for similar vents on Enceladus’ seafloor. So, could these particle possibly be microbes? Image via NASA/ JPL/ Space Science Institute. Previously undetected sub-micrometer particles have now been identified in the water vapo ..read more

View larger. | Artist’s concept of the rainbow-like glory on giant exoplanet WASP-76b. If confirmed, it will be the 1st glory on an exoplanet that astronomers have ever seen. Glories are common on Earth, but otherwise have only been seen on Venus so far. Image via ESA (ESA Standard License or CC BY-SA 3.0 IGO). Astronomers have detected what appears to be a glory – the same optical phenomenon you sometimes see out the window of an airplane – on on exoplanet, or planet orbiting a distant star. Glories are common on Earth, and spacecraft have seen them on Venus. But, if confirmed, this will be ..read more

Only 5 earthly spacecraft are headed out of solar system, into interstellar space. These are the Pioneers 10 and 11, Voaygers 1 and 2, and New Horizons. This image shows their approximate trajectories. Image (not to scale!) via NASA/ Johns Hopkins APL/ SwRI. The New Horizons spacecraft, launched in 2006, achieved historic flybys of Pluto in 2015 and Arrokoth in 2019, making it the fastest spacecraft ever sent from Earth. Chief scientist Alan Stern here provides an update, highlighting unexpected discoveries of dust impacts, an extended Kuiper Belt or even a second one, and outlines plans for ..read more

Massive dying stars explode in supernovas and emit large amounts of radiation. The radiation would be deadly to nearby planets with life. So what is the threat of supernovas to life on Earth? Image via NASA/ ESA/ Hubble SM4 ERO Team. By Chris Impey, University of Arizona The threat of supernovas to life on Earth Stars like the sun are remarkably constant. They vary in brightness by only 0.1% over years and decades, thanks to the fusion of hydrogen into helium that powers them. This process will keep the sun shining steadily for about 5 billion more years, but when stars exhaust their nuclear f ..read more