SpaceX will send one of the world’s most powerful telescopes into orbit

NASA has set its sights on SpaceX for the launch of its Nancy Grace Roman telescope. The observatory will help astronomers better understand the evolution of our Universe and unearth tens of thousands of new planets.

Since the launch of the James Webb Telescope in December 2021, it is probably the most anticipated observatory. The telescope Nancy GraceRoman will have a main mirror of 2.4m in diameter lined with a layer of silver less than four hundred nanometers thick. Its wide field of view will allow astronomers to better understand two of the greatest mysteries of modern astrophysics: the black matter and dark energy.

As a reminder, dark matter would be a form of matter that does not emit, absorb or reflect any light capable of explaining the movements of stars and galaxies. Dark matter would however have an abundance at least five times greater than baryonic matter, constituting about 27% of the total energy density of the observable Universe Dark energy would be a kind of force opposed to gravity responsible for accelerating the expansion of the universe.

This is what the Nancy Grace Roman Telescope will look like. Credits: NASA

A planet hunter

Astronomers also expect the Nancy Grace Roman Telescope to unearth new planets. To operate, the observatory must rely on the transit method and the microlens method.

As a reminder, the transit method consists in measuring the curve of light emitted by the stars to detect periodic dips in luminosity. These phenomena generally betray the passage of planets in front of their star from our point of view. Of the more than 5,000 extrasolar planets confirmed to date, more than half have been discovered using this method.

The gravitational microlens is itself a kind of “small version” of the gravitational lensing effect. This effect occurs when a foreground star aligns with a background star from our vantage point. The light from the second star will then be stretched and amplified by the gravitational field of the first. Depending on how that light behaves, astronomers can potentially determine the presence of planets.

These two methods have the advantage of complementing each other. The transit lens works best with planets close to their star, while the microlens lens detects planets far from their host stars. Note that the observatory will also be able to analyze stars located at more than 25,000 light years. For comparison, Kepler was monitoring stars at an average distance of about 2,000 light-years.

Finally, the telescope will also be equipped with a coronagraph that will block starlight. In doing so, researchers will be able to directly image the nearest exoplanets.

Nancy-Grace-Roman microlens
Principle of detection of a planet by the gravitational microlens method. Credits: Wikipedia

Launch in 2026

Note that the telescope was previously known as the Wide Field InfraRed Survey Telescope (WFIRST). It was renamed several years ago in honor of Dr. Nancy Grace Roman, considered the mother of Hubble.

Regarding the launch of the telescope, NASA has just awarded the contract to SpaceX. The agency will disburse here approximately $255 million. The launch will be with a rocket Falcon Heavy in October 2026 from Florida. Once in space, the observatory will be positioned around the Lagrange 2 point, just like the James Webb Telescope. Its primary mission is to last about five years.

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