Mars may be named after the god of war, but it seems more like a sappy romantic. NASA’s Mars Global Surveyor spacecraft spotted these hearts on the Martian surface throughout its time in orbit. All of them are natural formations, but let’s just go ahead and interpret them as love notes from the red planet. Image credit. NASA/JPL/Malin Space Science Systems.
Kate Howells • Jan 30, 2025
https://www.planetary.org/articles/should-you-be-worried-about-asteroid-2024-yr4
A recently discovered near-Earth asteroid, dubbed 2024 YR4, is making headlines because of the slim possibility that it could impact Earth on Dec. 22, 2032. Early observations suggest that it has about a 1% chance of colliding with our planet. So why all the fuss?
2024 YR4 is garnering so much attention because of more than 37,000 near-Earth asteroids already discovered, it is the only one with more than a 1 in 1,000 chance of impact. “It is rare to have an asteroid with a non-zero probability of hitting Earth,” said Heidi Hammel, Vice President for Science at the Association of Universities for Research in Astronomy and Vice President of the The Planetary Society’s board of directors.
To put it into context, 2024 YR4 has a Torino scale rating of as high as 3. The Torino Impact Hazard Scale ranges from 0 (no chance of impact) to 10 (certain impact likely to cause planetwide devastation). Ratings of 1 are fairly common among newly discovered asteroids, but follow-up observations have always reduced that rating to 0. Asteroid 2024 YR4’s rating of 3 is the second-highest an asteroid has ever reached. The only asteroid ranked higher was Apophis, discovered in 2004 and rated 4, but subsequently downgraded to 1 and then 0. We now know with certainty that Apophis will only pass close to Earth in 2029.
Right now, ESA estimates that 2024 YR4’s diameter is in the range of 40-100 meters (around 130-330 feet). If it did collide with Earth, an impactor of that size could cause an explosion in the atmosphere or even an impact crater, either of which could cause serious, even devastating, damage on the ground.
From Sky and Telescope
Fortuitously, the Planet of Love reaches greatest brilliancy on Valentine’s Day. At magnitude –4.9, it’s the equivalent of crushing a 1.4-day-old Moon into a point source. That’s bright! Bright enough to cast a shadow from a rural site on a moonless night. Count yourself lucky if you have snow cover. The added contrast makes it the perfect backdrop for shadow-spotting.
If you’re wondering what to give your love for Valentine’s Day, consider the nearest planet. In the movie It’s a Wonderful Life, the fictional character George Bailey offers to lasso the Moon for his future wife Mary Hatch. Why not brandish your own imaginary lasso and “pull down” Venus for your sweetheart? (Don’t forget to have a box of specialty chocolates as a backup.)
Space Weather News for Jan. 30, 2025
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WHAT ARE ‘MIYAKE EVENTS’? So you thought the Carrington Event was bad? Researchers have found evidence in tree rings of solar storms 10 times worse. The discovery of “Miyake Events” has placed dendrochronologists at the center of space weather research.
A WARNING FROM THE TREES: How bad can a solar storm be? Just ask a tree. Unlike human records, which go back hundreds of years, trees can remember solar storms for millennia.
Nagoya University doctoral student Fusa Miyake made the discovery in 2012 while studying rings in the stump of a 1900-year-old Japanese cedar. One ring, in particular, drew her attention. Grown in the year 774–75 AD, it contained a 12% jump in carbon-14 (14C), an isotope created by cosmic radiation. The surge was 20 times greater than ordinary fluctuations in cosmic rays. Other teams confirmed the spike in wood from Germany, Russia, the United States, Finland, and New Zealand. Whatever happened, trees all over the world experienced it.
Most researchers think it was a solar storm—an extraordinary one. Often, we point to the Carrington Event of 1859 as the worst-case scenario for solar storms. The 774-75 AD storm was at least 10 times stronger; if it happened today, it would floor modern technology. Since Miyake’s initial discovery, she and others have confirmed four more examples (7176 BC, 5259 BC, 664-663 BC, 993 AD). Researchers call them “Miyake Events.”
Right: The 774-775 AD carbon-14 spike. [more]
It’s not clear that all Miyake Events are caused by the sun. Supernova explosions and gamma-ray bursts also produce carbon spikes. However, the evidence tilts toward solar storms. For each of the confirmed Miyake Events, researchers have found matching spikes of 10Be and/or 36Cl in ice cores. These isotopes are known to trace strong solar activity. Moreover, the 774-75 AD Miyake Event had eyewitnesses; historical reports of auroras in China and England suggest the sun was extremely active around that time.
Miyake Events have placed dendrochronologists (scientists who study tree rings) in the center of space weather research. After Miyake’s initial discovery in 2012, the international tree ring community began working together to look for evidence of solar superstorms. Their collaboration is called “the COSMIC initiative.” COSMIC results published in a 2018 edition of Nature confirm that Miyake Events in 774-75 AD and 993 AD were indeed global. Trees on five continents recorded carbon spikes.
“There could be additional Miyake Events throughout the Holocene” says Irina Panyushkina, a member of the COSMIC initiative from the University of Arizona’s Laboratory for Tree-Ring Research. “Finding them will be a slow and systematic process.”
Above: A global map of COSMIC tree ring and ice core measurements [more]
“An important new source for annual 14C measurements are floating tree-ring records from Europe and the Great Lakes,” says Panyushkina. “These are very old rings that could potentially capture 14C spikes as far back as 15,000 years. Eventually, I believe we will have a complete record of Miyake Events throughout that period.”
Four more candidates for Miyake Events have recently been identified (12,350 BC, 5410 BC, 1052 C, and 1279 C). The candidate in 12,350 BC, identified from tree rings the French Alps, may be more than twice the size of any other Miyake Event. Confirmation requires checking trees on many continents and finding matching spikes of 10Be and 36Cl in ice cores.
A complete survey of Miyake Events could tell us how often solar superstorms occur and how much peril the sun presents to a technological society. Stay tuned for updates from the trees.
Space Weather News for Oct. 26, 2024
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AN X-CLASS DOUBLE SOLAR FLARE: Solar activity remains high with an X-class double solar flare on Oct. 26th. The explosion hurled an impressive CME into space, and it appears to have an Earth-directed component. Several big sunspots are turning toward Earth, so this could be the beginning of a week of stormy space weather. Full story @ Spaceweather.com.
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Click the picture to view the flare in action.
An M9.5-X1.8 class double flare on Oct. 26th. Extreme ultraviolet movie from NASA’s Solar Dynamics Observatory.
Space Weather News for Oct. 24, 2024
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BIG SUNSPOTS AND AN X-FLARE: A big group of new sunspots exploded this morning, producing an X3.3-class solar flare and an impressive CME. The CME will graze Earth on Oct. 26th, possibly causing a geomagnetic storm. More flares are in the offing as the sunspot group turns toward Earth. Full story @ Spaceweather.com.
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Space Weather News for Oct. 2, 2024
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X7-CLASS SOLAR FLARE: An Earth-facing sunspot exploded on Oct 1st (2220 UT), producing the second-strongest solar flare of Solar Cycle 25. The X7.1-category blast caused a shortwave radio blackout over Hawaii and hurled a CME into space. The CME could reach Earth and cause geomagnetic storms later this week. Updates @ Spaceweather.com.
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Above: The extreme ultraviolet flash from yesterday’s X7.1-class solar flare. Credit: NASA/SDO
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Radio waves from Elon Musk’s growing network of satellites are blocking scientists’ ability to peer into the universe, according to researchers in the Netherlands.
The new generation of Starlink satellites, which provide fast internet around the world, are interfering more with radio telescopes than earlier versions, they say.
The thousands of orbiting satellites are “blinding” radio telescopes and may be hindering astronomical research, according to Netherlands Institute for Radio Astronomy (ASTRON).
SpaceX, which owns Starlink, has not replied to a request from BBC News for comment.
The satellites provide broadband internet around the world, often to remote places, including challenging environments like Ukraine and Yemen.
They are also used to connect remote areas of the UK to fast internet. In 2022 tests showed that Starlink could deliver internet speeds four times faster than the average, according to the Department for Digital, Culture, Media and Sport.
But astronomers say this comes at a cost.
“Every time more of these are launched with these kinds of emission levels, we see less and less of the sky,” Professor Jessica Dempsey, director of ASTRON, told BBC News.
“We’re trying to look at things like the jets, which are emitted from black holes in the centre of galaxies. We also look at some of the earliest galaxies, millions and millions of light years away, as well as exoplanets,” she said, highlighting the areas the satellite radiation is affecting.
Interference from the second generation, or V2, satellites was found by ASTRON to be 32 times stronger than the first generation.
AFTERGLOW OF A CME: A CME struck Earth yesterday (July 25th at 1422 UT). The impact did not immediately cause a geomagnetic storm, but hours later a minor G1-class storm occured as Earth was passing through the CME’s magnetized wake. The afterglow was observed in Washington, Wisconsin and Maine. CME impact alerts: SMS Text
MAJOR FARSIDE SOLAR FLARE: The biggest flare of Solar Cycle 25 just exploded from the farside of the sun. X-ray detectors on Europe’s Solar Orbiter (SolO) spacecraft registered an X14 category blast:
Solar Orbiter was over the farside of the sun when the explosion occured on July 23rd, in perfect position to observe a flare otherwise invisible from Earth.
“From the estimated GOES class, it was the largest flare so far,” says Samuel Krucker of UC Berkeley. Krucker is the principal investigator for STIX, an X-ray telescope on SolO which can detect solar flares and classify them on the same scale as NOAA’s GOES satellites. “Other large flares we’ve detected are from May 20, 2024 (X12) and July 17, 2023 (X10). All of these have come from the back side of the sun.”
Meanwhile on the Earthside of the sun, the largest flare so far registered X8.9 on May 14, 2024. SolO has detected at least three larger farside explosions, which means our planet has been dodging a lot of bullets.
The X14 farside flare was indeed a major event. It hurled a massive CME into space, shown here in a coronagraph movie from the Solar and Heliospheric Observatory (SOHO):
The CME sprayed energetic particles all over the solar system. Earth itself was hit by ‘hard’ protons (E > 100 MeV) despite being on the opposite side of the sun.
“This is a big one–a 360 degree event,” says George Ho of the Southwest Research Institute, principal investigator for one of the energetic particle detectors onboard SolO. “It also caused a high dosage at Mars.”
SolO was squarely in the crosshairs of the CME, and on July 24th it experienced a direct hit. In a matter of minutes, particle counts jumped almost a thousand-fold as the spacecraft was peppered by a hail storm energetic ions and electrons.
“This is something we call an ‘Energetic Storm Particle’ (ESP) event,” explains Ho. “It’s when particles are locally accelerated in the CME’s shock front [to energies higher than a typical solar radiation storm]. An ESP event around Earth in March 1989 caused the Great Quebec Blackout.”
So that’s what might have happened if the CME hit Earth instead of SolO. Maybe next time. The source of this blast will rotate around to face our planet a week to 10 days from now, so stay tuned. Solar flare alerts: SMS Text
An asteroid will pass between Earth and Moon just a day before Asteroid Day! Good timing, but the scary thing is that it was only discovered last week.
Remember Apophis? This asteroid made headlines when it was thought it would impact Earth in 2029. It won’t, but it might take out a few communication satellites. It will likely be visible to the naked eye.
The U.S. government recently completed an asteroid impact preparedness exercise. NASA’s Planetary Defense Coordination Office, in partnership with the Federal Emergency Management Agency and the U.S. Department of State Office of Space Affairs, recently went through a hypothetical scenario in which an asteroid was found on a collision course with Earth. This was the fifth such exercise, and the first to incorporate the results of NASA’s DART mission. NASA published a summary of takeaways from the exercise.
Two large asteroids will safely pass Earth this week. Although both asteroids’ trajectories are known and neither poses any risk to our planet, one of them was only discovered a week ago, highlighting the need to continue improving our ability to detect potentially hazardous objects. That recently discovered asteroid, 2024 MK, will be observable around its closest approach on June 29 using a small telescope or binoculars.
Apophis won’t hit Earth, but might wipe out a few satellites!Apophis is a near-Earth asteroid, meaning its orbit around the Sun brings it within 1.3 times the distance between the Sun and Earth. Its full name is Apophis 99942. After Apophis was discovered in 2004, the asteroid was given a 2.7% chance of hitting Earth in 2029, causing a great deal of media attention. It also for a time had a small chance of hitting Earth in 2036. Additional observations have shown it will not hit Earth in 2029 or in 2036.
Nevertheless, in 2029 Apophis will come closer to Earth than our geostationary communications satellites, likely sparking a great deal of public interest. READ MORE
The asteroid was only discovered earlier this month
Earth is surrounded by rocky bodies and bits of debris from when the solar system formed roughly 4.5 billion years ago. On Saturday, one of those leftover rocks will whiz past Earth.
The asteroid is called 2024 MK and, at its closest, it will pass roughly 290,000 km from Earth. While we have plenty of small asteroids that are scattered within Earth’s orbit, this one is sizeable, ranging anywhere from 120 metres to 260 metres in diameter.
But there’s another interesting — and somewhat disquieting — fact about this large asteroid.
“Maybe the big take-home point on this one is it’s a pretty big object and it was only found 10 or 12 days before closest approach,” said Peter Brown, Canada Research Chair in meteor astronomy and a professor at Western University in London, Ont. “The last time we had an object this big or bigger pass this close to Earth was … in 2001.”
“So unlike most asteroid stories, this actually is noteworthy in the sense of … this is pretty big, pretty close.”
