Posts

Alien life likely can't survive on exoplanets smaller than Mars, scientists say

Image
A rocky planet orbiting in the habitable zone of a sun-like star may look like a perfect place for life to thrive — but not if it's too small to hold onto its atmosphere. So, we may wonder: How much smaller Earth could be and still have its delightfully breathable atmosphere ? How small could an exoplanet be to sustain life as we know it? With these questions in mind, University of California Riverside planetary scientist Michelle Hill and her colleagues recently simulated what happens to the atmospheres of different sizes of rocky worlds. The worlds tested were similar to Earth and orbited in the habitable zones around sun-like stars . It turns out for a world to maintain an atmosphere long enough for life to gain a foothold (a few billion years at minimum), it needs to be at least as big as Mars . Narrowing down the search for life The habitable zone — the area around a star where tempera...
Post a Comment
Read more

Space Force orders 36 more Golden Dome missile-tracking satellites, for $1.75 billion

Image
The U.S. Space Force is adding three dozen spacecraft to its growing constellation designed to detect and track incoming missiles from orbit. The Space Development Agency (SDA) announced the agreements, worth a combined $1.75 billion, on July 14, naming L3Harris Technologies and Sierra Space as the recipients. Each company will provide 18 Accelerated Missile Defense Tranche 3 (AMDT3) spacecraft, for a total of 36 satellites that will grow the SDA Proliferated Warfighter Space Architecture's Tranche 3 Tracking Layer constellation, part of the Trump Administration's Golden Dome initiative. All 36 are expected to be ready for launch by the end of 2028, according to an SDA statement . SDA's contracts with each company differ slightly. One calls for "18 missile warning and missile tracking variant space vehicles" from Sierra Space, while the other requests "18 missile defe...
Post a Comment
Read more

SpaceX Falcon 9 rocket sends Starlink satellites to orbit a day after rare launch abort

Twenty-four Starlink satellites reached low Earth orbit on Tuesday (July 21), a day later than originally scheduled due to a last-second rocket engine abort. SpaceX at first tried to launch the broadband internet relay units on a Falcon 9 rocket on Monday morning (July 20), but an unexpected engine cutoff at the point of ignition scrubbed the day's attempt . The company did not provide a reason for the abort. By Tuesday, whatever the problem was had been addressed and the Falcon 9 was ready to fly. It liftoff off at 10:49 a.m. EDT (1449 GMT; 7:49 a.m. PDT local time) from Space Launch Complex 4 East at Vandenberg Space Force Base in California. About an hour later, after a normal ascent, the new Starlink batch ( Group 17-39 ) were deployed into their intended orbit. "Deployment of 24 Starlink satellites confirmed," SpaceX posted on social media . Previous Booster B1082 missions: ...
Post a Comment
Read more

Billions of miles and thousands of years in the making: This is the life of a Perseid shooting star

Image
Picture it: A slash of vivid green light splits the starry sky. There for a moment and then gone, leaving nothing but a short-lived glowing trail and a moment of pure joy. You've finally caught it, your first Perseid shooting star of the season. What you saw was the final moment of a story billions of miles and thousands of years in the making. A story that began with that same shooting star locked inside the icy body of the wandering comet 109P/Swift-Tuttle. The 16-mile-wide (26 kilometer) giant of a comet spends its life journeying back and forth between the outer and inner solar system, where its frigid body is heated by the sun , triggering dramatic outbursts of activity. While in close proximity to our star, ice near to the surface of the comet is transformed into gas, skipping the water stage entirely as it escapes out into the vastness of interplanetary space. Embedded within that i...
Post a Comment
Read more

Scientists discover mystery molecule on Pluto and Saturn's moon Titan: 'We cannot say what it is'

Image
Separated by billions of miles and shaped by very different environments, Saturn's smoggy moon Titan and the dwarf planet Pluto have, on paper, little in common. Titan is a geologically active world cloaked in an atmosphere denser than Earth's, its landscape shaped by seas of liquid methane and vast dunes built from organic particles that rain out of its skies. Pluto, by contrast, is a frigid outpost with a tenuous atmosphere hovering above an icy, frozen surface. Yet, observations from the James Webb Space Telescope (JWST) have revealed these two disparate worlds share an identical, unexplained infrared signature on their surfaces — a sign that similar chemistry may be unfolding on both worlds despite their stark differences, scientists say. Detailed in a new study , the feature appears at precisely the same infrared wavelength on both Titan and Pluto, indicating that it absorbs light...
Post a Comment
Read more

50 years after Viking 1's historic Mars landing, NASA is looking to the Red Planet's skies

Image
Half a century after first putting hardware down on Mars, NASA is looking to explore the Red Planet's skies. On July 20, 1976, the Viking 1 lander touched down in the western reaches of Chryse Planitia (the "Golden Plain"), a large circular landform that lies 22.5 degrees north of the Martian equator. It was the first-ever Mars landing for NASA. Viking 1, along with its twin Viking 2, went on to conduct the first fully successful mission on the Red Planet's surface. (The Soviet Union's Mars 3 probe survived its touchdown attempt on Dec. 2, 1971 but died less than two minutes later.) And those missions have left a rich and intriguing legacy. The first color image ever captured on the surface of Mars. NASA's Viking 1 lander took this photo on July 21, 1976. (Image credit: NASA) Viking 1 and Viking 2 — which touched down in a different Red Planet region on Sept. 3, 1976 ...
Post a Comment
Read more

Scientists detect hidden skin damage before it becomes visible

Scientists have discovered a hidden warning sign of skin damage that appears before collagen fibers visibly thin, break, or lose their connections. Using advanced light-based techniques, the team found that collagen’s carefully organized molecular “handedness” can collapse even while the tissue still appears structurally intact and contains the same amount of collagen. This suggests that skin may begin deteriorating at a much deeper level long before conventional imaging can detect a problem. from Latest Science News -- ScienceDaily https://ift.tt/VcdA5Lm
Post a Comment
Read more