Access Nature and 54 other Nature Portfolio journals
Get Nature+, our best-value online-access subscription
$29.99 / 30 days
cancel any time
Subscribe to this journal
Receive 51 print issues and online access
$199.00 per year
only $3.90 per issue
Rent or buy this article
Prices vary by article type
Prices may be subject to local taxes which are calculated during checkout
Updates & Corrections
Correction 19 July 2021: An earlier version of this story stated that space is a shared, but ungoverned, realm. International agreements such as the 1967 Outer Space Treaty guide what nations can and cannot do in space.
Hainaut, O. R. & Williams, A. P. Astron. Astrophys. 636, A121 (2020).