Professor Mark Sims on the discovery that Beagle 2 made it to the surface

Observers in the British Isles with a clear sky one hour after sunset on 24 August should find a location that offers an unobstructed view of the south-southwest horizon. Here you will see first-magnitude star Antares in the constellation Scorpius, Mars and Saturn all in a line easily encompassed by low-power binoculars in the bright twilight.

NASA’s Mars Pathfinder probe dropped to the surface of Mars for an airbag-cushioned landing 20 years ago Tuesday, bouncing 15 times across an ancient flood plain before deploying a mobile robot to usher in two decades of uninterrupted Martian exploration.

Europe’s ExoMars rover will not be ready for launch in 2018, officials said Monday, forcing a two-year delay for the ambitious mission to drill into the Martian surface and search for the remnants of past life.