A star like our Sun only shines the way it does because of its intrinsic balance. Stars are massive, and the inward gravitational pressure from all that mass acts to contain the outward thermal pressure from all the fusion inside the star. They are in equilibrium, or on the main sequence if you like, and the result is a spherical mass of plasma that holds its shape and emits radiation with relative stability for billions of years. Like our Sun.
Space News & Blog Articles
JUICE is having problems extending its radar antenna. Astronomers watch a star eat its planet. A design for a space station with artificial gravity.
The surface of Mars is a pretty desolate place at first glance. The soil is many times as dry as the driest desert on planet Earth, the temperatures swing from one extreme to the other, and the air is incredibly thin and toxic. And yet, there’s ample evidence that the planet was once much warmer and wetter, with lots of flowing and standing water on its surface. Over time, as Mars’ atmosphere was slowly stripped away, much of this water was lost to space, and what remains is largely concentrated around the poles as glacial ice and permafrost.
In a recent study published in The Astronomical Journal, a researcher from the École Polytechnique Fédérale de Lausanne (EPFL) discusses the potential reasons why we haven’t received technoemission, also called technosignatures, from an extraterrestrial intelligence during the 60 years that SETI has been searching, along with recommending additional methods as to how we can continue to search for such emissions.
During the recent ViaSat-3 launch on a Falcon Heavy rocket, SpaceX released the protective spacecraft fairing at the highest altitude ever attempted. Therefore, the fairing reached incredible speeds during its fiery re-entry through the Earth’s atmosphere. Fortunately, there was a camera on board so we could watch. At one point, the one half of the fairing was traveling 15 times faster than the speed of sound, releasing a trail of plasma in its wake as it returned to Earth.
No matter where we go in the universe, we’re going to need water. Thus far, human missions to Earth orbit and the Moon have taken water with them. But while that works for short missions, it isn’t practical in the long term. Water is heavy, and it would take far too much fuel to bring sufficient water to sustain long-term bases on the Moon or Mars. So we’ll have to use the water we can extract locally.
One of the great questions about our solar system is: what was it like as it formed? We know that a protosolar nebula birthed the Sun and planets. And, we know planets in our solar system have slightly different orbital inclinations, probably due to some interesting dynamics in the birth crèche. Why is that? The answer may be in a slightly weird-looking protoplanetary disk circling the newborn star TW Hydrae.
Stars emit powerful flares that can be deadly for any burgeoning life on nearby planets. Images from spacecraft that monitor the Sun show these flares in glorious, horrifying detail. But the flares from the Sun are mere nuisances compared to some stars. Some stars produce catastrophic superflares, which can be tens of thousands of times more energetic than the Sun’s. That much energy can sterilize a planet’s surface.
Of the thousands of meteorites found on Earth, about 188 have been confirmed to be from Mars. How did they get here? Over the tumultuous history of our Solar System, asteroids have smashed into Mars with such force, the debris was blasted into space and then drifted through space, eventually entering the Earth’s atmosphere, and surviving the journey to the ground.
The Force is with us, according to cosmologists working to understand a mysterious “something” that’s making the universe expand. Its name? Dark energy. And, it turns out that it’s been present everywhere throughout cosmic history.
The first stars were odd ducks. Nobody’s observed them yet (although astronomers are hopeful JWST might spot them someday) but their ghosts remain. Born more than 13.5 billion years ago, they were very different from most of those we know today. These were massive monsters made mostly of hydrogen and helium. And, when they exploded as supernovae, their “starstuff” got scattered to space. Astronomers have now found the chemical remains of those stars in three distant gas clouds observed by European Southern Observatory’s Very Large Telescope.
The Moon dominates our view of the night sky. But it’s not the only thing orbiting Earth. A small number of what scientists call quasi-satellites also orbit Earth.
According to the most widely-accepted cosmological model, the majority of the mass in our Universe (roughly 85%) consists of “Dark Matter.” This elusive, invisible mass is theorized to interact with “normal” (or “visible”) matter through gravity alone and not electromagnetic fields, neither absorbing nor emitting light (hence the name “dark”). The search for this matter is ongoing, with candidate particles including Weakly-Interacting Massive Particles (WIMPs) or ultralight bosons (axions), which are at opposite extremes of the mass scale and behave very differently (in theory).
In honor of Black Hole Week, NASA’s Scientific Visualization Studio has released an amazing video showing how several supermassive black holes scale with our solar system. It’s definitely worth checking out because it’s an excellent example of just how overwhelmingly huge some black holes are.
The number of known extrasolar planets has exploded in the past few decades, with 5,338 confirmed planets in 4,001 systems (and another 9,443 awaiting confirmation). When it comes to “Earth-like” planets (aka. rocky), the most likely place to find them is in orbit around M-type red dwarf stars. These account for between 75 and 80% of all stars in the known Universe, are several times smaller than the Sun and are quite cool and dim by comparison. They are also prone to flare activity and have very tight Habitable Zones (HZs), meaning that planets must orbit very closely to get enough heat and radiation.
If we ever find life on other worlds, it is unlikely to be a powerful message from space. It’s certainly possible that an alien civilization specifically sends us a radio message like a scene out of Contact, but the more likely scenario is that we observe some kind of biological signature in an exoplanet’s atmosphere, such as oxygen or chlorophyll. But as a recent study shows, that could be more difficult than we thought.
In a scene eerily reminiscent of the Galileo spacecraft’s antenna issues, ESA’s Jupiter Icy Moons Explorer (JUICE) is having a problem with an antenna. The 16-meter-long radar Radar for Icy Moons Exploration (RIME) unit is stuck on a tiny pin that’s keeping it from deploying fully.
Astronomers recently shared a new image captured by the Hubble Space Telescope of the galaxy NGC 4395. This relatively diffuse and dim dwarf galaxy is located just 14 million light-years from Earth.
The International Space Station (ISS) is nearing the end of its service. While NASA and its partners have committed to keeping it in operation until 2030, plans are already in place for successor space stations that will carry on the ISS’ legacy. China plans to assume a leading role with Tiangong, while the India Space Research Organization (ISRO) plans to deploy its own space station by mid-decade. NASA has also contracted with three aerospace companies to design commercial space stations, including Blue Origin’s Orbital Reef, the Axiom Space Station (AxS), and Starlab.
An instrument called ShadowCam is giving NASA’s planned Artemis missions to the Moon some advanced views of a landing site. It’s mounted to the Danuri Korea Pathfinder Lunar orbiter sent to the Moon last year. Lately, this amazing camera has been sending back some highly detailed images of the lunar north and south pole regions.