Several missions this year are seeking out life on the red planet. But would we recognize extraterrestrials if we found them?
NASA has shortlisted four proposals for its next astrophysics missions, due for launch in 2025. The agency has funding to fly two of them, and the four will now each receive funds for a nine-month period of technical study. The two missions will be chosen next year.
From Sagan to Tesla, scientists have long puzzled over how to talk to extraterrestrial intelligence.
For the past 200 years, the problem of interstellar communication with an extraterrestrial intelligence has vexed some of the world’s greatest scientists and mathematicians. Carl Friedrich Gauss, the mathematician and inventor of the heliotrope, suggested using a large array of mirrors; Guglielmo Marconi and Nikola Tesla, pioneers of wireless communication, found a solution in radio waves; and John McCarthy and Marvin Minsky, the progenitors of artificial intelligence, wanted to send computers into space as our extraterrestrial envoys.
What do you ask the man who knows everything? The theoretical physicist and bestselling author answers questions from famous fans and Observer readers
Not since the 1960s have we witnessed such appetite for space missions. Here’s what to expect in the year ahead, from commercial launches to Chinese ambitions