In 2029, sky watchers may catch a glimpse of at least one human-made ‘star’ in the sky.
Earlier this week, NASA announced plans to place a small satellite in orbit just over 35,400 kilometers above our planet’s surface – far enough so that the satellite can mimic a real star for telescopes at Soil. Scientists say the satellite, called Landolt, wouldn’t be bright enough to be seen with the naked eye, but if you have a personal telescope at home you might be able to see an object the size of a shoebox hovering over the United States. in a stationary position.
The mission’s primary goal is to help calibrate telescopes on Earth and create new, more accurate catalogs of the brightness of real stars.
Once in orbit, the satellite will beam eight lasers aboard ground-based telescopes, which will observe the ‘artificial star’ in the same frame as their science targets. After measuring how much of the lasers’ light – which would have a predetermined brightness – is absorbed by our planet’s atmosphere, astronomers can compare it to about 60 real stars, giving the stars’ brightness as seen from Earth , is cataloged more accurately than conventional methods can. reaches.
“Lasers inside room is a pretty cool selling point, just like getting started on a mission,” said a member of the mission team Jamie Tayaran assistant professor of astronomy at the University of Florida, said in a rack. “But scientifically speaking, what we’re trying to do here is really fundamental.”
Related: Bark! Meow! Clock! NASA uses lasers to send photos of dogs, cats and chickens to the ISS
Better catalogs of star brightnesses will increase the accuracy with which various properties of stars, such as their brightness, size and age, are measured. This accuracy, in turn, could allow scientists to refine other measurements that also depend on the brightness and distances of stars. For example, stellar dynamics like these help us measure the the age of the universe and how quickly it has expanded time. Astronomers can also more accurately deduce how much energy comes from stars, which could ease the search for orbit exoplanets with potentially life-threatening conditions.
‘There are so many big questions astronomy: How did we get here? Are there other planets like ours? Do aliens exist?” Tayar said. “But those are really difficult questions, and to answer them the measurements have to be really good, and they have to be right.”
Normally, astronomers rely on it to measure the universe stars called ‘standard candles’, which can be compared to light bulbs of a known wattage. The brightness and distance factors for these stars are well established and are therefore used as a tool to measure distances between other stars or galaxies and Earth. However, those measurements were made in the 1990s and ‘have become the main source of error in temperature measurements Brightness for a majority of the stars,” said a press release by the University of Montreal in Canada, which is involved in the mission.
“If we look at a star with a telescope, no one today can tell you with the accuracy you want how many photons come out or how bright the star is,” he says. Peter Plavchan from George Mason University, the mission’s principal investigator. “We will now know exactly how many photons per second come from this source with an accuracy of 0.25 percent.”
Data from the $19.5 million Landolt mission will reduce uncertainties in star brightness measurements from 10 percent to one percent, astronomers say. ‘That makes a difference when extended to the properties of exoplanets and, believe it or not, to some of the parameters used to determine the structure of exoplanets. the universe,” said Angelle Tanner of Mississippi State University, who is leading the mission’s science and managing a $300,000 subgrant, in another rack.
The mission is named in honor of the late American astronomer Arlo Landolt, who is best known for his photometric standard star lists, which are widely used as calibration benchmarks when studying new objects in the sky. Mission control will take place on the campus of George Mason University in Fairfax County, Virginia, in collaboration with scientists from twelve institutions. The payload itself will be built by the U.S. Department of Commerce’s National Institute of Standards and Technology, headquartered in Maryland.