Venus
19
Mercury
2
Sun
10
Missions
Earth
INNER SOLAR SYSTEM
Mission OriginU.S.U.S.S.R./RussiaEuropeU.S./EuropeJapanChinaGermanyIndiaIsraelLIFE ON MARS?
A procession of robotic craft have
explored Mars from all angles,
discovering a world that was once
much wetter and warmer—and
might even have supported life.
Each colored linerepresents a missionsince 1973 that stud-ied a celestial body.Lines are arranged inchronological orderfrom the object out-ward. Dotted linesare failed missions.Nearly half a century has elapsed since humans last visite
But we never stopped exploring. We’ve inhabited research
(right) and sent robotic craft (below) to venture even fart
selfies on Mars, plunge into Jupiter, and investigate our s
AFTER APOLLO
OBJECT SIZES AND ORBITAL DISTANCES ARE NOT TO SCALE.n the 1960s our moon was
still very much a mystery.
To learn the most from
the Apollo visits, NASA selected
landing sites in a variety of lunar
terrains, including the dark, flat
plains sculpted by vanished lava
oceans and highlands formed by
meteor impacts.
From 1969 to 1972, U.S. astro-
nauts landed at six sites, each
chosen for different scientific
objectives. All of them were on the
moon’s mottled near side, where
the terrain had been studied
extensively by lunar orbiters and
Mission Control could remain in
direct contact with the astronauts.
Space agencies have sent probes,
with no people on them and thus
no need to worry about human
safety, to visit far-flung places in
the solar system. Spacecraft have
explored 60 other moons and even
set down on one, Saturn’s Titan.
On our own moon, robotic rovers
have left tracks at four sites.
China made history earlier
this year by setting its Chang’e 4
lander on the moon’s far side.
The first private lander to reach
the moon crashed in April, but the
Israeli nonprofit behind it quickly
announced plans to try again.
Not to be outdone, the U.S.
intends to send a series of landers
with technology to lay the ground-
work for astronauts to return.
I