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Illustration: Aïda Amer/Axios
Scientists can’t agree on the answer to a foundational question in physics — how fast the universe is expanding — and to some, the debate signifies that their understanding of the universe may be about to shift.
The big picture: Cosmologists have been debating the expansion rate of the universe — known as the Hubble Constant — for decades, but today’s controversy centers on two camps that disagree on just how fast our 13.8 billion-year-old universe is moving.
Why it matters: The Standard Model — which Dennis Overbye of the New York Times calls "a collection of theories describing all the physical forces except gravity" — still has its limitations. Cosmologists are looking for a way to "break" the model in order to figure out exactly what they're missing.
Where it stands: Cosmologists using data from the Planck telescope's map of the cosmic microwave background emitted during the early days of the universe place the Hubble Constant at about 67 kilometers per second per megaparsec.
The catch: If both values are shown to be correct, then it would mean that the universe is expanding at a rate that defies our best predictions, effectively breaking the Standard Model.
But, but, but: A recent study using red giant stars to gauge expansion puts the constant in between the late and early universe values, hinting that the true answer may lie somewhere in the middle.
The bottom line: It’s too early to say whether our understanding of the universe is about to undergo a seismic shift, but scientists are paying close attention to any new data that could deepen our understanding of it.
Thousands of galaxies seen by the Hubble Space Telescope. Photo: NASA/ESA/STScI
The Hubble Constant controversy is inspiring scientists to find new and inventive methods for testing just how fast our universe is expanding.
What's next: Researchers are now looking to a variety of different kinds of stars and other observations to try to nail down what the Hubble Constant actually is.
Yes, but: In the immediate future, scientists will continue to parse the early and late universe numbers with a fine-toothed comb in the hopes that perhaps some overlooked element will help bring the numbers closer together.
Read more: Cosmologists debate how fast the universe is expanding (Quanta)
The remnant of a supernova. Photo: NASA/CXC/F. Vogt et al./ESO/VLT/MUSE/STScI
Radioactive dust sent out by ancient supernovas has been found in Antarctica, according to a new study in the journal Physical Review Letters.
The big picture: Researchers behind the study suggest that our solar system is currently flying through a cloud of cosmic material thought to be shaped by supernovas.
What they found: The team behind the study thinks that the iron-60 atoms found in the region were delivered to Earth in the last 20 years.
What's next: Koll and his colleagues are hoping to get a look at older Antarctic snow in order to compare concentrations of iron-60 in the past to those found today.
A Falcon Heavy rocket launch in June. Photo: SpaceX
Four companies — SpaceX, Blue Origin, United Launch Alliance (ULA) and Northrop Grumman — have submitted proposals to become 1 of 2 launch providers for the U.S. Air Force from 2022 to 2026.
Why it matters: Launching commercial and government payloads to orbit is a competitive business, and locking in billions of dollars in revenue from the Air Force would be a huge win for any of these companies.
The intrigue: All 4 companies have submitted their bids to the Air Force, but the fight to get to this point has been a long one, and it's not over yet.
Happy birthday, Curiosity. Photo: NASA/JPL-Caltech/MSSS
Astronomers spot flashes from our galaxy's black hole (Ryan F. Mandelbaum, Gizmodo)
Inside Rocket Lab's plan to reuse its rocket (Michael Sheetz, CNBC)
ESA confirms 2nd ExoMars parachute test failure (Jeff Foust, Space News)
Blue Origin protests Air Force launch competition (Axios)
Curiosity has been on Mars for 7 years (Axios)
The Seagull Nebula. Photo: ESO/VPHAS+ team/N.J. Wright (Keele University)
The Seagull Nebula takes on a red hue in a new photo taken by the European Southern Observatory's VLT Survey Telescope.
If you haven't spotted it yet, the seagull's head is the bulbous mass of gas and dust on the lower right, with its wings spreading out to the left.
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