Natalie Wolchover writes: To look back in time at the cosmos’s infancy and witness the first stars flicker on, you must first grind a mirror as big as a house. Its surface must be so smooth that, if the mirror were the scale of a continent, it would feature no hill or valley greater than ankle height. Only a mirror so huge and smooth can collect and focus the faint light coming from the farthest galaxies in the sky —…
Jonathan O’Callaghan writes: Bob O’Dell wasn’t quite sure what he was looking at. It was 1992, and he had just got his hands on new images from the Hubble Space Telescope that zoomed in on young stars in the Orion Nebula. O’Dell had been hoping to study the nebula itself, an interesting region of star formation relatively close to Earth. Yet something else caught his attention. Several of the stars didn’t look like stars at all, but were instead enveloped…
Virat Markandeya writes: David McComas has a favorite “astrosphere,” the environment created by a star’s stellar wind as it buffets the surrounding interstellar medium. It belongs to a star named Mira. In an image from 2006, Mira is heading to the right, at 291,000 miles an hour, five times the speed our sun ambles through its local interstellar cloud in the Milky Way. You can make out a “bow shock” forming ahead of the star, like one would ahead of…
Physics Today reports: Three-quarters of the asteroids orbiting the Sun are of the carbon-rich C-type, whose significant freight of hydrated minerals has a similar ratio of deuterium to hydrogen as the water in Earth’s oceans. Asteroids of all types were far more abundant when Earth’s oceans formed around 4.6 billion years ago. Unsurprisingly, asteroids are a leading contender for the source of Earth’s water. But how many of those ancient asteroids could have found themselves in orbits that sent them…
Caleb Scharf writes: One of my favorite albeit heavily paraphrased quotes from Albert Einstein is his assertion that the most incomprehensible thing about the universe is that it is comprehensible. (What he actually said, in his 1936 work “Physics and Reality,” is more longwinded, and includes a digression into Immanuel Kant and the meaning of “comprehensibility,” but he does write “… the eternal mystery of the world is its comprehensibility.”) In truth, this statement holds back a little. The greater…
Douglas Preston writes: If, on a certain evening about sixty-six million years ago, you had stood somewhere in North America and looked up at the sky, you would have soon made out what appeared to be a star. If you watched for an hour or two, the star would have seemed to grow in brightness, although it barely moved. That’s because it was not a star but an asteroid, and it was headed directly for Earth at about forty-five thousand…
Matthew Bothwell writes: There’s an iconic moment, filmed in the shadow of the Very Large Array in New Mexico, that many people who visit this giant telescope try to duplicate. A young astronomer sits cross-legged on the bonnet of her car, the towering line of radio dishes vanishing into the distance behind her. With her laptop in front of her, she’s listening intently to a giant pair of headphones, held upside down so that the strap hangs below her chin….
Robin George Andrews writes: We like to think of ourselves as unique. That conceit may even be true when it comes to our cosmic neighborhood: Despite the fact that planets between the sizes of Earth and Neptune appear to be the most common in the cosmos, no such intermediate-mass planets can be found in the solar system. The problem is, our best theories of planet formation — cast as they are from the molds of what we observe in our…
Corey S Powell writes: What determines our fate? To the Stoic Greek philosophers, fate is the external product of divine will, ‘the thread of your destiny’. To transcendentalists such as Henry David Thoreau, it is an inward matter of self-determination, of ‘what a man thinks of himself’. To modern cosmologists, fate is something else entirely: a sweeping, impersonal physical process that can be boiled down into a single, momentous number known as the Hubble Constant. The Hubble Constant can be…
Nature reports: A survey of the southern sky has reconstructed how mass is spread across space and time, in the biggest study of its kind. The data provide striking evidence that dark energy, the force that appears to be pushing the Universe to accelerate its expansion, has been constant throughout cosmic history. The Dark Energy Survey (DES) collaboration revealed its results in an online briefing on 27 May and in several papers posted online. The DES team observed the sky…
Jordana Cepelewicz writes: Scientists poke and prod at the fringes of habitability in pursuit of life’s limits. To that end, they have tunneled kilometers below Earth’s surface, drilling outward from the bottoms of mine shafts and sinking boreholes deep into ocean sediments. To their surprise, “life was everywhere that we looked,” said Tori Hoehler, a chemist and astrobiologist at NASA’s Ames Research Center. And it was present in staggering quantities: By various estimates, the inhabited subsurface realm has twice the…
The Associated Press reports: A few days ago, millions of tons of super-heated gas shot off from the surface of the sun and hurtled 90 million miles toward Earth. The eruption, called a coronal mass ejection, wasn’t particularly powerful on the space-weather scale, but when it hit the Earth’s magnetic field it triggered the strongest geomagnetic storm seen for years. There wasn’t much disruption this time — few people probably even knew it happened — but it served as a…
Live Science reports: The night sky is becoming increasingly filled with shiny satellites and space junk that pose a significant threat to our view of the cosmos, as well as astronomical research, a new study warns. The researchers found that the more than 9,300 tons (8,440 metric tons) of space objects orbiting Earth, including inoperative satellites and chunks of spent rocket stages, increase the overall brightness of the night sky by more than 10% over large parts of the planet….
Gideon Lewis-Kraus writes: Leslie Kean is a self-possessed woman with a sensible demeanor and a nimbus of curly graying hair. She lives alone in a light-filled corner apartment near the northern extreme of Manhattan, where, on the wall behind her desk, there is a framed black-and-white image that looks like a sonogram of a Frisbee. The photograph was given to her, along with chain-of-custody documentation, by contacts in the Costa Rican government; in her estimation, it is the finest image…
Emily Levesque writes: If you ask an astronomer to choose the single most exciting picture in all of astronomy, many of us will point to a familiar orange ring. At a glance it may not look like much — a fuzzy glowing doughnut, bulging slightly at the bottom and, as of last month, streaked with curving lines — but in reality this unassuming circle is humanity’s first glimpse of a black hole, with the colors chosen not to mimic realism,…
Shannon Stirone writes: There’s no place like home—unless you’re Elon Musk. A prototype of SpaceX’s Starship, which may someday send humans to Mars, is, according to Musk, likely to launch soon, possibly within the coming days. But what motivates Musk? Why bother with Mars? A video clip from an interview Musk gave in 2019 seems to sum up Musk’s vision—and everything that’s wrong with it. In the video, Musk is seen reading a passage from Carl Sagan’s book Pale Blue…