Watching the Sun

People have been sending spacecraft to watch our star since the 1960s, and a queue of new ones is being assembled right now. This page is the real record, then the plans, then the idea at the far end of the runway: using the Sun itself as a telescope lens big enough to photograph the surface of a planet around another star.

Flown missions, funded builds and published concepts. A swarm on the scale modelled here would be the next rung on a ladder that already exists. The Sun's dossier carries the live view from one of these spacecraft right now.

The whole line, by launch year

Each mark is a spacecraft. Hover for the name, click to jump to it. Colour is what it is doing now.

hover a mark

The far end: the Sun as a telescope

Gravity bends light. The Sun bends it enough that rays grazing its edge come to a focus, and anything parked beyond that focus sees the Sun working as a lens hundreds of billions of times more powerful than any mirror we could launch. The focus starts around 550 times the Earth to Sun distance, well past everything else in this catalogue.

What it would buy, if it were ever flown: not a dot, and not an artist's impression, but a genuine image of the surface of a planet around another star, with continents and weather resolved. What it costs is the hard part: a sail-driven craft, decades of travel to reach 550 AU and beyond, and a way to hold station while scanning the ring of light the Sun draws around itself. Every entry above is a published study. None has flown.

Where a swarm would sit on that ladder

The swarm modelled here is not one of these missions. It takes what the line above proves is possible, multi-point observation from many vantage points at once, and asks what happens when it stops being done one spacecraft at a time. The scale page is where you decide how far to push that.