Earth is constantly bombarded by fragments of rock and ice that have drifted from space, known as meteoroids. Most of these are about the size of a grain of sand or a pebble, and burn up completely high in the atmosphere. Meteoroids larger than a golf ball can be meteor Or a shooting star On a dark and clear night.
While very small meteorites are common, meteorites larger than a dishwasher are not uncommon.
The meteor is Aerospace and Geophysicist Normally, man-made objects are not suitable for study because it is impossible to predict when and where they will hit the atmosphere. However, on very rare occasions, it is possible to study man-made objects that enter the atmosphere, such as meteorites.
These objects are space A mission designed to deliver samples of extraterrestrial material from space EarthDue to its similarity to a meteorite’s impact, the Sample Return Capsule (SRC) is often referred to as the “artificial meteorite.”
Recently, more than 80 researchers from more than a dozen institutions collaborated to study such “artificial meteors.” NASA’s OSIRIS-REx sample return capsule – It occurred upon re-entering Earth’s atmosphere.
Related: The first examination of samples from the asteroid Bennu suggests the space rocks could be “fragments of an ancient ocean world.”
These institutions include Sandia National LaboratoriesNASA Jet Propulsion Laboratory, Los Alamos National Laboratory, Defense Threat Reduction Agency, TDA Research Inc., University of Hawaii, Air Force Research Laboratory, Black Nest Nuclear Weapons Facility, Boise State University, Idaho National Laboratory, Johns Hopkins University, Kochi University of Technology, Nevada National Security Site, Southern Methodist University, University of Memphis and Oklahoma State University.
This sample return gave our team a unique opportunity to measure sound waves and other phenomena generated by objects from space as they pass through Earth’s atmosphere.
To capture the signals, numerous highly sensitive microphones and other equipment were placed at strategic locations close to SRC’s flight path.
While space agencies and private companies launch objects into space, time, Osiris Rex The SRC is one of the few objects to have returned to Earth from interplanetary space since the end of the Apollo program, as these are the only objects capable of achieving the same speeds as natural meteoroids. Their re-entry is valuable. To study the properties of natural objects.
Asteroid sample collection
National Aeronautics and Space Administration (NASA) Origin, Spectral Interpretation, Resource Identification, Security, Regolith Explorer, or Osiris RexThe mission was completed on September 8, 2016. Near-Earth Asteroid Bennuand samples were taken from its surface in October 2020.
Specimen, sample Returned to Earth Launched in a sample return capsule in the early morning of September 24, 2023, the SRC re-entered the atmosphere over the Pacific Ocean at speeds of more than 27,000 miles per hour (43,500 kilometers per hour), landing in Utah just minutes later.
SRC generates shock waves As it penetrates deeper into the atmosphere, a shock wave appears that resembles the sonic boom produced by a supersonic jet plane. Breaking the sound barrierThe shock wave then subsides, leaving only a low frequency sound. It is called infrasound.
Humans cannot hear infrasound, but sensitive scientific instruments can detect it from great distances. These instruments can be ground-based or suspended in the air from balloons.
Observation of SRC
Our team of scientists saw the SRC’s re-entry as an opportunity to learn more about meteors. Siddharth Krishnamoorthi NASA Jet Propulsion Laboratoryused the SRC’s re-entry to test an infrasound detection balloon that could later be used in space. Venus.
Another team led by one of us – Elizabeth Silver – and Danny Bowman Researchers at Sandia National Laboratories used the SRC to better understand how sound can be harnessed. [gather information about meteoroids].
These observation campaigns involved researchers from many institutions across the country.
Our team strategically placed instruments over a 300-mile (482 km) stretch from Eureka, Nevada, to near the landing site in Utah. The instruments ranged from high-tech, custom sensors to smartphones on the ground around the SRC’s flight path and landing site to monitor infrasound waves during SRC re-entry.
In addition to ground-based sensors, the researchers mounted instruments on balloons that floated at twice the altitude of a commercial airliner during the SRC’s re-entry. These balloon-mounted sensors recorded sound waves generated by the SRC’s shock wave. These sound waves conveyed information about the SRC, its movements, and the environment it passed through.
The balloon team had to time it carefully to make sure the balloon was in the right position when the SRC passed by. NASA Jet Propulsion Laboratory, Oklahoma State University and Sandia National Laboratories Several types of balloons were launched before dawn from Eureka, Nevada.
OSU, Sandia National Laboratories, University of Hawaii They also placed ground-based infrasound sensors at the Utah-Nevada border, close to the SRC’s landing site, and at Wendover Airport, which detected clear infrasound signals even though SRC had already slowed and Wendover Airport was about three times farther down the flight path than the Eureka site.
Researchers from these teams are currently analyzing the data to identify the points in orbit where instruments recorded the SRC re-entry signal. Because the SRC’s flight path was approximately 300 miles (482 km), researchers need to determine where the signal originated when it was detected by various sensors.
This is the most measured Historical hypersonic reentries.
This work will help our team understand the pattern in which the low-frequency sound waves propagated through the atmosphere and where the shock waves peaked.
Our team is still analyzing the data, but preliminary results show that our instrument captured many signals that will be useful for future research using infrasound waves to study meteors.
By understanding the complex mechanisms behind how low-frequency sound waves travel through the atmosphere, researchers could use infrasound to detect dangers on Earth. Tornadoes, etc. avalanche.
