Sending tiny telescope past Saturn could solve some of universe's mysteries

November 22, 2021

Dozens of space-based telescopes operate near Earth and provide incredible images of the universe. But imagine a telescope far away in the outer solar system, 10 or even 100 times farther from the Sun than Earth. The ability to look back at our solar system or peer into the darkness of the distant cosmos would make this a uniquely powerful scientific tool.

We’d need only send a very small telescope – with a lens roughly the size of a small plate – to achieve some truly unique astrophysical insights. Such a telescope could be built to weigh less than 20 pounds (9 kilograms) and could be piggybacked on virtually any mission to Saturn or beyond.

Though small and simple compared with telescopes like Hubble or James Webb, such an instrument operating away from the bright light of the Sun could make measurements that are difficult or outright impossible from a vantage point near the Earth.

Unfortunately for astronomers, getting a selfie of the solar system is a challenge. But being able to see the solar system from an outside vantage point would reveal a lot of information, in particular about the shape, distribution and composition of the dust cloud that surrounds the Sun.

Another benefit of placing a telescope far from the Sun is the lack of reflected light. The disc of dust in the plane of the planets reflects the Sun’s light back at Earth. This creates a haze that is between 100 and 1,000 times brighter than light from other galaxies and obscures views of the cosmos from near Earth. Sending a telescope outside of this dust cloud would place it in a much darker region of space making it easier to measure the light coming from outside the solar system.

Once there, the telescope could measure the brightness of the ambient light of the universe over a wide range of wavelengths. This could provide insights into how matter condensed into the first stars and galaxies. It would also enable researchers to test models of the universe by comparing the predicted sum of light from all galaxies with a precise measurement.