NASA Downgrades the Risk of 2024 YR4 to Below 1%
NASA astronomers have been continuing to evaluate the future orbits of asteroid 2024 YR4. It was initially estimated to be around a 1.3% chance of impact; that number rose to 3.1% with further calculations and observations. Good news, the number is dropping again. Today the agency calculated that the chance of an impact is 0.28%, while the chance of an impact with the Moon rose to 1%. Future observations are planned with JWST, so stay tuned.
Read the full story by Mark Thompson
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New Explanation Mars' Color // Big Moon Launch // Space Refuelling Test
The asteroid threat is down to zero, whatever happened to that star that was supposed to go nova, more landers are launched to the Moon. Plus in our extended version on Patreon, how Venus's atmosphere could protect life in its clouds.
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How Astronomers Make Deep Maps of the Milky Way
Astronomers have built up highly accurate and detailed maps of the Milky Way; tricky, considering we're currently embedded inside it. How do they do it? They rely on the tendency of hydrogen atoms to occasionally release a photon with a wavelength of exactly 21 centimeters. This radiation can travel long distances and pass through gas and dust that normally obscure our view of these regions. As they map out the clouds of hydrogen, they map out the galaxy's spiral arms.
Read the full story by Paul M. Sutter
Sampling Enceladus' Subsurface Ocean With TIGRE Mission Concept
Ocean worlds are fascinating targets for study, but Enceladus has geysers, emptying its insides into space and making it the ideal destination for a future mission. Researchers recently presented a fascinating mission concept at the AGU 2024 Fall Meeting called Thermal Investigation of Geothermal Regions of Enceladus (TIGRE). This would consist of an orbiter, lander, and drill, sampling the material coming from Enceladus from space and at the source near its geysers.
Read the full story by Laurence Tognetti
New Study Proposes That Cosmic Radiation Altered Virus Evolution in Africa
Earth has been bombarded by cosmic rays throughout its entire 4.5 billion year history, but the radiation load increases when nearby supernovae pop off. Now, researchers think that a supernova that went off about 2.5 million years ago might have had a significant enough effect on Earth that it altered the evolution of viruses in Africa. Scientists studied samples from Lake Tanganyika and suggested the radiation could have been linked to an increased number of viruses.
Read the full story by Matt Williams
Glaciers Worldwide are Melting Faster Causing Sea Levels to Rise More
As global temperatures continue to rise, this is leading to increased glacier melting. According to a new survey, satellite data indicate that the world's glaciers have declined by about 5% over the last 20 years, losing 273 billion tonnes of ice a year, on average. These rates aren't evenly distributed across the planet, with Antarctica only losing 2% of glacier mass, while central Europe has seen up to 39%.
Read the full story by Matt Williams
We Know How Much Radiation Astronauts Will Receive, But We Don't Know How to Prevent it
When human astronauts make the trip to Mars, they'll be spending months in deep space in both legs of the journey, exposed to the direct radiation of space. NASA's recent Artemis 1 mission was only a few weeks, but it has given researchers a baseline to estimate what the potential radiation load astronauts could expect to receive on a Mars journey. These data confirmed previous models of radiation estimates and provided some surprises about shielding strategies.
Read the full story by Mark Thompson
Although it Lacks a Magnetic Field, Venus Can Still Protect With in its Atmosphere
Unlike Earth, Venus lacks an internal dynamo and a planetwide magnetosphere that could protect any life from solar and cosmic radiation. But it does have an extremely thick atmosphere. Planetary scientists recently simulated the atmosphere of Venus and calculated how much space radiation would penetrate down to the lower cloud deck. They found that the atmosphere is sufficiently thick to protect life at Venus's "habitable altitude" of 40–60 km.
Read the full story by Mark Thompson
One of the Most Massive Black Holes in the Universe Lurks at the Center of the Cosmic Horsehoe
The Cosmic Horseshoe is a spectacular gravitational lens, in an almost perfect Einstein Ring. The enormous gravity of a foreground galaxy cluster is magnifying the light from a more distant galaxy into a circle around it. And now, astronomers have worked out that the galaxy cluster contains a supermassive black hole with 36 billion times the mass of the Sun, one of the most massive ever measured in the Universe.
Read the full story by Evan Gough
A Hybrid Hydrogen Drive Train Could Eliminate Aircraft Emissions
As the world attempts to decarbonize its power, transportation, and industrial sectors, air travel will be a difficult transition. There aren't easy solutions to replace the energy density of jet fuel. A new NASA NIAC grant has been awarded to investigate a hybrid hydrogen drivetrain. This would allow an aircraft to use both a hydrogen fuel cell and a gas turbine to power the aircraft, converting hydrogen into electricity to power the aircraft's turbines.
Read the full story by Andy Tomaswick
Can We Develop a More Accurate Habitable Zone Using Sulfur?
The habitable zone is where planets could have liquid water on their surfaces, but not if they're actually habitable. In a new paper, astronomers propose a new way to map the inner edge of habitable zones by searching for sulfur dioxide (SO₂) in the atmospheres of exoplanets. If there's SO₂, this indicates that the planet doesn't have liquid water on its surface. Telescopes like Webb could scan planets for SO₂, creating a more accurate map of habitable zones.
Read the full story by Brian Koberlein
SpaceX Consuming NASA, Earth Hoarding Asteroids, Tracking X37 | Q &A 298
Will SpaceX eventually consume NASA? Are there asteroids at Lagrange points in front and behind the Earth? Can we track the Space Force's secret X37 shuttle? Answering all these questions and more in this Q&A show.
This Laser Could Find Fossil Microbes on Mars
NASA's Perseverance Rover has been tasked with finding evidence for the conditions of life on Mars, now or in the past. And maybe it could even find life itself. It doesn't have a microscope on board, but the rover is equipped with its SuperCam laser instrument, which can scan rocks for organic compounds. Now, NASA scientists are working on an even better version that could detect evidence of microbial fossils on Mars and has already been tested in Earth's deserts.
Read the full story by Evan Gough
A New Explanation for Why Mars is Red
Mars is the "Red Planet" because of its red soil, and it was long believed that it was caused by the same chemical process that creates rust on Earth, emerging from dry conditions on Mars. Now, researchers have mimicked the conditions of Mars in the lab and have a new explanation: it's actually a chemical called ferrihydrite, an iron oxide that contains water. This would mean that its characteristic red color is due to a time when the planet was covered in water.
Read the full story by Mark Thompson
So This is How You Get Magnetars
Magnetars are a type of neutron star with the most powerful magnetic fields in the universe. They're formed by the death of massive stars, like pulsars and other neutron stars. So, what creates such intense magnetic fields? Thanks to a new simulation, astronomers have discovered that a magnetar probably forms when material ejected by the supernova explosion falls back down onto the star's surface, amplifying its dynamo effect.
Read the full story by Brian Koberlein
As Expected, the Threat From 2024 YR4 has Essentially Dropped to Zero
Astronomers have completed more observations of asteroid 2024 YR4, charting its future trajectory with even more accuracy. Previous estimates put the chance of an impact with Earth in 2032 as high as 2.8%. The new conclusion is that the asteroid's chance of striking Earth is down to 0.001%. This is a very common story: when an asteroid is first found, the uncertainty is high, and it could be a future threat to Earth. Then, later observations bring that down to zero.
Read the full story by Evan Gough
Rover Finds the Shoreline of an Ancient Beach on Mars
Mars is cold and dry today, but the Red Planet was believed to be covered in oceans. Now, scientists examining data sent home by China's Zhurong rover think they've identified the shoreline, with sandy beaches lapped by waves. Zhurong's landing spot was chosen with this exact goal: going to a place on Mars that was thought to be the transition from an ocean to land. Its radar looked under the surface and found a structure that matched beach deposits on Earth.
Read the full story by Carolyn Collins Petersen
Perseverance Takes A Second Look At Some Ancient Rocks
Perseverance has found some rocks in Jezero Crater, which are so fascinating that scientists have sent it back for a second look at an exposed outcrop called Tablelands, which has deposits of serpentine, a mineral that forms in the presence of water. The first time it sampled a rock, its sample container tube was empty, as the rock turned to dust. So, it traveled a small distance, took another sample, and failed. It finally got one after the third attempt.
Read the full story by Evan Gough
Is T Coronae Borealis About to Light Up?
Remember that nova that was supposed to brighten in T Corona Borealis? Whatever happened to it? The first brightening was seen in 1866 and then in 1946, and that means we should be due for another brightening, following its 80-year cycle. But the arrival seems overdue. Recently, astronomers have noticed an increasing temperature and accretion activity from the star to the white dwarf that could indicate that the nova is right around the corner.
Read the full story by David Dickinson
What if Mars Had Air, Destiny of Stars, Fraserverse Movies | Q&A 299
Would we have colonized Mars by now if it had air? What is the ultimate fate of stars? What's the point of talking about the density of black holes? And which movies would go into the Fraserverse? Answering all these questions and more in this Q&A show.
The Solar System is Taking a Fascinating Journey Through the Milky Way
About 14 million years ago, the Solar System flew through the Orion star-forming complex - home of the Orion Nebula - which might have compressed the heliosphere, allowing more interstellar dust to reach Earth. This transition seems to match the Middle Miocene Climate Transition, when a warm variable climate shifted to a cooler climate, creating an early version of the Antarctic ice sheet. This could mean that interstellar dust has influenced past Earth's climate.
Read the full story by Evan Gough
Mars's Northern Ice Cap is Surprisingly Young
In even the smallest backyard telescope, you can see the prominent ice caps at both of Mars's poles. Although the planet was probably warm enough to have liquid water on its surface, all that remains are these thick ice sheets at its poles. Astronomers assumed that these caps were ancient, formed at some point in the last few billion years when Mars lost its water. But new evidence shows that the northern sheet is young, forming between 2 and 12 million years ago.
Read the full story by Carolyn Collins Petersen
Lucy Sees its Next Target: Asteroid Donaldjohanson
On April 20th, NASA's Lucy mission will come within 960 km of the asteroid Donald Johanson, completing another appetizer of science before it reaches its destination in Jupiter's Trojan belt. It's a tiny moving point of light today, but over the next few months, it will get bigger and bigger until Lucy can resolve features on its 3-km-wide surface. The asteroid was named for anthropologist Donald Johanson, who discovered the original "Lucy" skeleton.
Read the full story by Evan Gough
DARPA Wants to Build Structures in Orbit, Without Needing a Launch From Earth
Any satellite launched into space has to handle Earth's gravity and the rigors of launch until it can finally arrive in the weightless environment it was built for. But what if you could launch durable raw materials and then construct your satellite in orbit? DARPA is partnering with several universities to demonstrate 3D printing and orbital assembly of satellite parts and recently put out a new request for proposals to explore biological growth mechanisms in space.
Read the full story by Mark Thompson
Photonic Lightsails are our Best Shot at Reaching Another Star
Chemical rockets can only get us so far. In order to reach another star system, we'll need a more energy-dense propellant or use a beam of energy to accelerate a spacecraft to relativistic speeds—a photonic lightsail. A new paper explores the benefits and downsides of lightsails, calculates what configuration would be best to carry a small payload to another star within a human lifetime, and investigates the materials that could make it possible.
Read the full story by Mark Thompson
A Giant Ribbon Can Pull Payloads Along
You're probably familiar with the concept of a solar sail by now, where a gossamer sheet of reflective material can receive an accelerating force from radiation alone. Researchers have proposed a dramatically different type of solar sail and were awarded a NASA NIAC Phase 1 grant to explore it. It's called "The Ribbon" and would carry a payload on one end of a long, thin fabric. This would make it much more stable and easier to deploy and stow than a giant rectangle.
Read the full story by Andy Tomaswick
Could Neutrinos Tell Us About the Inside of the Sun?
Neutrinos are produced by fusion reactions in the Sun, passing effortlessly through its dense interior. Different reactions produce neutrinos with different energies, and researchers think this could be a way they could probe the interior of the Sun. Various Earth-based solar neutrino observatories are catching neutrinos hurled by the Sun, which can be compared to those produced by nuclear reactors. This will allow astronomers to build up an interior map of the Sun.
Read the full story by Mark Thompson
How Brine Shrimp Adapted to Mars-Like Conditions
We're learning that Earth life is surprisingly hardy and could even be resilient to Mars-like conditions. Bacteria, archaea, mosses, lichens, and even tardigrades could handle the conditions of Mars (if they found water). Now, researchers wanted to know if brine shrimp could handle Mars-like conditions. They placed shrimp cysts in Mars-like pressure conditions and then analyzed them after they hatched into full shrimp and found they adapted well to the environment.
Read the full story by Matt Williams
A Chinese Satellite Tests Orbital Refuelling
Perfectly functional spacecraft have to cease operations because they run out of propellant for stationkeeping. Now a Chinese satellite has demonstrated practical orbital refueling. The recently launched Shijian-25 satellite docked with the Beidou-3 G7 at geosynchronous orbit and transferred 142 kilograms of hydrazine, extending the communication satellite's lifespan by 8 years. China is planning to build a network of "space gas stations" to maintain its fleet.
Read the full story by Mark Thompson
China's Tianwen-2 Is About to Launch. Here's What We Know About Its Target Kamo'Oalewa
China's Tianwen-2 spacecraft recently arrived at the launch site for its upcoming May 2025 mission to asteroid Kamoʻoelewa. This mission will collect samples from the 40-100 meter asteroid and deliver them to Earth by 2027. Kamoʻoelewa is a small, "quasi-satellite" of Earth with an unusually rapid rotation rate. A team of astronomers put out a new paper describing their most recent observations of Kamoʻoelewa and the outstanding scientific questions.
Read the full story by David Dickinson
A New Way to Measure Where the Milky Way's Dark Matter Is
The Milky Way has about 5 times as much dark matter compared to its regular matter, but what form does it take? Is it a vast, smooth halo of invisible particles or in clumps, concentrated in different areas? For the last few years, astronomers have used binary millisecond pulsars, recording the signals of their radio pulses, but these are rare. Now, researchers have also developed a way to measure the signals from solitary pulsars, which are much more common.
Read the full story by Carolyn Collins Petersen
Rogue Planets are Born in Young Star Clusters
Astronomers have found many examples of rogue planets drifting between stars, and even found large numbers of them in star-forming regions like the Orion Nebula. Researchers are studying how these free-floating planets could form in nebulae, and the mechanisms that could set them loose to wander the galaxy. They found that circumstellar disks can get too close, causing instabilities that shed planetary objects into escape trajectories.
Read the full story by Evan Gough
Other Interesting Space Stuff
- NASA Employees Advised to Delay Responses to "What did you do" Email
- Hubble Completes the Largest Galactic Mosaic of all-Time
- How Mapping Galaxies can Teach us What the CMB can't
- How Charges and Masses Create the Universe Around us
- 4 key Steps to Transform the USA Back Into a Scientific Nation
- Did the Snowball Earth Give Complex Life a Boost?
- Ask Ethan: Does Mass or Energy Increase Near the Speed of Light?
Thanks!
Fraser Cain
Publisher
Universe Today
As always, if you have comments or questions, or suggestions on how I can improve this newsletter, please don't hesitate to reply this email or email me at info@universetoday.com.
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