Around 14,000 known asteroids orbit in our solar system, without representing any risk to the Earth’s surface. However, it is possible that there are thousands that remain undiscovered and may be in trajectory to crash on our planet’s surface. Nevertheless, it remains a mystery how big they are and what are their physical features.

Scientists are increasingly concerned about these unknown asteroids since its size can be relevant if the Earth is on their course. A big asteroid crashing at the surface could generate a cataclysm. Therefore, there is practical perspective in finding asteroids, and it is actually a very relevant task, but there are different perspectives on how to approach this labour.

Killer asteroids under scrutinity
Scientists are increasingly concerned about unknown asteroids since its size and other physical characteristics are relevant if the Earth is on their course. Credit: National Geographic

NEOWISE project

The NEOWISE project is an initiative created by NASA’s Planetary Science Division to hunt and identify those potentially risky asteroids. It is part of a larger mission called the Wide-field Infrared Survey Explorer or WISE. Using WISE’s ability to take space images, NEOWISE analyses data of asteroids, comets and other solar system objects.

The project already discovered around 34,000 solar systems objects and provided detections of more than 158,000 minor planets. This information is used by the NASA to create a database on the sizes, orbits and compositions of asteroids in order to detect early threats. The goal is to learn more about the near-Earth objects that may represent a possible hazard to the planet.

The Agency released the first observations made by NEOWISE in 2015. Since then, the observations have continued. So far, about 90 percent of the coverage planned to be executed in the project has been done. Currently, NEOWISE is making around 450,000 infrared measurements of at least 19,000 different solar system objects.

The goal is to create a final catalogue describing properties of asteroids, comets and minor planets identified throughout the mission. The principal investigator for the project is Amy Mainzer of the Jet Propulsion Laboratory, the responsible office of carrying out the operations at the headquarters at the California Institute of Technology.

NASA vs. Dr. Myhrvold

Nathan P. Myhrvold, a former chief technologist at Microsoft, provided his own analysis of the NEOWISE measurements, questioning NASA’s mechanisms to understand killer asteroids. According to Dr. Myrhvold, the NEOWISE reports are deeply flawed, stating that most results are “all wrong and inaccurate.”

The scientific journal Icarus published Myrhvold’s perceptions, first released at Cornell University, on the WISE spacecraft and the NEOWISE project. He considers that the scientific community does not recognise their ignorance in space matters, stating that “they do not know as much as they think they do.”

Myrhvold addresses to the modeling methods of NASA, arguing that law of thermal radiation should be applied to these observations since not using the thermal modeling can limit the possibility to determine the asteroids’ features like the possible composition, size, temperature, reflectivity of the surface and other physical properties. Information that may be key to determine whether the space object represents a risk or not.

On the other hand, NASA dismissed Mr. Myrhvold’s statements. It clarified that NEOWISE estimations are accurate, since the error range is around the 10 percent of the actual size of the asteroids observed, considering that uncertainties are not as great as Myrhvold argues. Although the Space Science Institute considers that the input provided by Myrhvold is useful taking into account the awareness it raises in the matter of error analysis, alerting the scientific community to not assume things that are still unknown.

Myrhvold has dedicated the last few years to disregard scientific data and statistics in several fields, like investigation on dinosaurs and most recently planetary investigation. To some scientific communities, his considerations are useful to enrich scientific knowledge, while some other consider him a non-qualified individual to question studies.

Source: Arxiv