Astronomers have found greater than 5,000 planets outdoors of the photo voltaic system so far. The grand query is whether or not any of those planets are house to life. To discover the reply, astronomers will probably want extra highly effective telescopes than exist at this time.
I’m an astronomer who research astrobiology and planets round distant stars. For the final seven years, I’ve been co-leading a crew that’s growing a brand new form of house telescope that could accumulate 100 instances extra mild than the James Webb Space Telescope, the most important house telescope ever constructed.
Almost all house telescopes, together with Hubble and Webb, accumulate mild utilizing mirrors. Our proposed telescope, the Nautilus Space Observatory, would exchange giant, heavy mirrors with a novel, skinny lens that’s a lot lighter, cheaper, and simpler to provide than mirrored telescopes. Because of those variations, it could be potential to launch many particular person items into orbit and create a robust community of telescopes.
The want for bigger telescopes
Exoplanets—planets that orbit stars aside from the Sun—are prime targets within the seek for life. Astronomers want to make use of large house telescopes that accumulate enormous quantities of sunshine to review these faint and faraway objects.
Existing telescopes can detect exoplanets as small as Earth. However, it takes much more sensitivity to start to study in regards to the chemical composition of those planets. Even Webb is simply barely highly effective sufficient to go looking sure exoplanets for clues of life—specifically gases within the ambiance.
The James Webb Space Telescope price greater than $8 billion and took over 20 years to construct. The subsequent flagship telescope will not be anticipated to fly earlier than 2045 and is estimated to price $11 billion. These formidable telescope initiatives are all the time costly, laborious, and produce a single highly effective—however very specialised—observatory.
A new form of telescope
In 2016, aerospace large Northrop Grumman invited me and 14 different professors and NASA scientists—all consultants on exoplanets and the seek for extraterrestrial life—to Los Angeles to reply one query: What will exoplanet house telescopes appear like in 50 years?
In our discussions, we realized {that a} main bottleneck stopping the development of extra highly effective telescopes is the problem of creating bigger mirrors and getting them into orbit. To bypass this bottleneck, a couple of of us got here up with the thought of revisiting an previous expertise known as diffractive lenses.
Conventional lenses use refraction to focus mild. Refraction is when mild adjustments path because it passes from one medium to a different—it’s the purpose mild bends when it enters water. In distinction, diffraction is when mild bends round corners and obstacles. A cleverly organized sample of steps and angles on a glass floor can type a diffractive lens.
The first such lenses have been invented by the French scientist Augustin-Jean Fresnel in 1819 to offer light-weight lenses for lighthouses. Today, comparable diffractive lenses will be discovered in lots of small-sized client optics—from digital camera lenses to digital actuality headsets.
Thin, easy diffractive lenses are infamous for his or her blurry photos, in order that they have by no means been utilized in astronomical observatories. But when you could enhance their readability, utilizing diffractive lenses as an alternative of mirrors or refractive lenses would permit an area telescope to be less expensive, lighter, and bigger.