25 January 2004: Mars Exploration Rover–B, named Opportunity, landed at Meridiani Planum on the surface of Mars at 5:05 a.m., UTC SCET (Spacecraft Event Time) and rolled into a small crater, approximately 22 meters (72 feet) in diameter.
The crater would later be named Eagle Crater, and the landing site is named Challenger Memorial Station. The site is on the opposite side of the planet from Opportunity‘s twin, MER-A, Spirit.
23 January 2003: The final, very weak signal from Pioneer 10 was received on January 23, 2003 when it was 12 billion kilometers (80 Astronomical Units) from Earth.
The space probe was launched from Earth at 01:49:00 UTC, 2 March 1972, aboard an Atlas Centaur rocket.
“On January 1, 2016, Pioneer 10 was predicted to be 114.07 a.u. from the Earth (about 10 billion miles); and traveling at 12.04 km/s (26,900 mph) (relative to the Sun) and traveling outward at about 2.54 a.u. per year. Voyager 2 is projected to pass Pioneer 10 by April 2019. Sunlight takes 14.79 hours to reach Pioneer 10. The brightness of the Sun from the spacecraft is magnitude −16.6. Pioneer 10 is heading in the direction of the constellation Taurus.
“If left undisturbed, Pioneer 10 and its sister craft Pioneer 11 will join the two Voyager spacecraft and the New Horizons spacecraft in leaving the Solar System to wander the interstellar medium. The Pioneer 10 trajectory is expected to take it in the general direction of the star Aldebaran, currently located at a distance of about 68 light years. If Aldebaran had zero relative velocity, it would require more than two million years for the spacecraft to reach it.” — Wikipedia
4 January 2004, 04:35 Ground UTC: The NASA Mars Exploration Rover A, named Spirit, landed on the surface of Mars within the large impact crater Gusev. The location of touch down and the starting point for the rover’s exploration of Mars is named Columbia Memorial Station.
3 December 1973: At 02:26:00 UTC, the NASA interplanetary probe Pioneer 10 reached its closest approach to the gas giant, Jupiter, 132,252 kilometers (82,178 miles) above the planet’s cloud tops. At that time, Pioneer 10 had a velocity of approximately 132,000 kilometers per hour (82,021 miles per hour).
During the encounter with Jupiter, more than 500 photographic images were made and transmitted to Earth. A variety of measurements were made by sensors aboard the space craft.
Pioneer 10 was built by the TRW Space & Technology Group, Redondo Beach, California, for the NASA Ames Research Laboratory. It was launched by a three-stage Atlas Centaur rocket from Launch Complex 36A, Kennedy Space Center, Cape Canaveral, Florida, 2 March 1972.
The last signal received from Pioneer 10 was on 23 January 2003. At that time, the probe was an estimated 12 billion kilometers (80 Astronomical Units) from Earth.
22 October 1975, 05:13 UTC: The lander from the Soviet space probe Venera 9 touched down on the surface of the planet Venus, at approximately 32° south latitude, 291° east longitude.
The images and other data was transmitted to an orbiting section of Venera 9 for relay to Earth. The lander sent signals for approximately 53 minutes before the orbiter traveled out of range.
Venera 9 had been launched from the Baikonur Cosmodrome aboard a Proton-K rocket, 8 June 1975. The space probe weighed 4,936 kilograms (10,882 pounds).
Once in orbit around Venus, the spacecraft separated into the orbiter and lander. As the lander descended to the surface, data was collected about the planet’s atmosphere. A 40-kilometer (25-mile) deep layer of clouds was studied. The cloud bases were about 35–40 kilometers (22–25 miles) above the surface. The clouds contained hydrochloric and hydrofluoric acid, bromine and iodine.
At the planet’s surface the atmospheric pressure was 90 times that of Earth’s. The temperature was measured at 485 °C. (905 °F.).