一 | Washington, Oct 12 (UNI) American space agency NASA says its recent attempt to deflect the path of an asteroid was successful, after its Dart probe struck an asteroid head-on.
Scientists have now confirmed the orbit of a 160m-wide space rock known as Dimorphos was altered when the Dart probe struck it head on last month.
Researchers came to the conclusion after making measurements using a range of space and Earth-based telescopes.
The mission was conceived to test a potential strategy to defend the Earth against threatening objects.
Dart's achievement proves such an idea would work, provided it was initiated early enough and the target wasn't overly massive.
"This mission shows that Nasa is trying to be ready for whatever the Universe throws at us," said agency administrator Bill Nelson.
"I believe that Nasa has proven that we are serious as a defender of the planet," he told reporters.
The space agency released a raft of data on Tuesday to support its assessment, including new pictures from the Hubble Space Telescope and from a small Italian spacecraft that stood off from the impact by about 50km (30 miles).
The Double Asteroid Redirection Test (Dart) took place some 11 million km (7 million miles) from Earth.
It saw the refrigerator-sized Nasa satellite drive straight into Dimorphos at 22,000km/h (14,000mph), destroying itself in the process.
The space rock orbits a much larger (780m wide; 2,550ft) object called Didymos. Before impact, the time taken for Dimorphos to make one circuit of its sibling was 11 hours and 55 minutes.
The telescope evidence now indicates this orbital period has been reduced to 11 hours and 23 minutes - a change of 32 minutes. This corresponds to Dimorphos moving closer into to Didymos by "tens of metres".
Nasa had defined a minimum successful period change of Dimorphos of 73 seconds or more. The results released on Tuesday show Dart surpassed this benchmark by more than 25 times.
"This is a 4 percent change in the orbital period of Dimorphos around Didymos. Dart just gave it a small nudge. But if you wanted to do this in the future, you'd want to do it years in advance," commented Nancy Chabot from the Johns Hopkins University Applied Physics Laboratory, which led the mission for Nasa.
"Warning time is really key here in order to enable this sort of asteroid deflection to be used in the future as part of a much larger planetary defence strategy."
Nasa's Dart programme scientist, Tom Statler, also had a word of caution about drawing too many conclusions from the experiment.
Asteroids came in many different guises, he said. Their compositions and constructions were diverse - something that was being emphasised every time a mission visited a new object.
"We should not be too eager to say one test on one asteroid tells us exactly how every other asteroid would behave in a similar situation," he stressed.
"But what we can do is use this test as an anchor point for our physics calculations in our simulations that tell us how different kinds of impacts in different situations should behave."
Four years from now, the European Space Agency (Esa) will have three spacecraft - collectively known as the Hera mission - at Didymos and Dimorphos to make follow-up studies.
UNI ING。 After serving more than a month of in-school suspension over his dreadlocks, a Black student in Texas was told he will be removed from his high school and sent to a disciplinary alternative education program on Thursday.Darryl George, 18, is a junior at Barbers Hill High School in Mont Belvieu and has been suspended since Aug. 31. He will be sent to EPIC, an alternative school program, from Oct. 12 through Nov. 29 for “failure to comply” with multiple campus and classroom regulations, the principal said in a Wednesday letter provided to The Associated Press by the family.Principal Lance Murphy wrote that George has repeatedly violated the district's “previously communicated standards of student conduct." The letter also says that George will be allowed to return to regular classroom instruction on Nov. 30 but will not be allowed to return to his high school's campus until then unless he's there to discuss his conduct with school administrators.Barbers Hill Independent School District prohibits male students from having hair extending below the eyebrows, ear lobes or top of a T-shirt collar, according to the student handbook. Additionally, hair on all students must be clean, well-groomed, geometrical and not an unnatural color or variation. The school does not require uniforms.George's mother, Darresha George, and the family's attorney deny the teenager's hairstyle violates the dress code. The family last month filed a formal complaint with the Texas Education Agency and a federal civil rights lawsuit against the state’s governor and attorney general, alleging they failed to enforce a new law outlawing discrimination based on hairstyles. The family alleges George's suspension and subsequent discipline violate the state’s CROWN Act, which took effect Sept. 1. The law, an acronym for “Create a Respectful and Open World for Natural Hair,” is intended to prohibit race-based hair discrimination and bars employers and schools from penalizing people because of hair texture or protective hairstyles including Afros, braids, dreadlocks, twists or Bantu knots. A federal version passed in the U.S. House last year, but was not successful in the Senate.The school district also filed a lawsuit in state district court asking a judge to clarify whether its dress code restrictions limiting student hair length for boys violates the CROWN Act. The lawsuit was filed in Chambers County, east of Houston.George’s school previously clashed with two other Black male students over the dress code. Barbers Hill officials told cousins De’Andre Arnold and Kaden Bradford they had to cut their dreadlocks in 2020. Their families sued the district in May 2020, and a federal judge later ruled the district’s hair policy was discriminatory. Their pending case helped spur Texas lawmakers to approve the state’s CROWN Act. Both students withdrew from the school, with Bradford returning after the judge’s ruling. ___AP journalist Juan Lozano contributed to this report from Houston.___The Associated Press education team receives support from the Carnegie Corporation of New York. The AP is solely responsible for all content.。
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