Home > Astronomical History, Ephemeris Program, History, Holiday, Planetary exploration > 07/04/2022 – Ephemeris – Space firsts, or attempts, on our nation’s birthday

07/04/2022 – Ephemeris – Space firsts, or attempts, on our nation’s birthday

July 4, 2022

This is Ephemeris for Independence Day, Monday, July 4th. Today the Sun will be up for 15 hours and 28 minutes, setting at 9:31, and it will rise tomorrow at 6:03. The Moon, 2 days before first quarter, will set at 12:53 tomorrow morning.

To celebrate our nation’s 200th birthday, NASA attempted to land the Viking 1 lander on the planet Mars on July 4th, 1976. The Viking was a combination orbiter and lander and had a twin spacecraft arriving almost two months later. Viking 1 entered orbit on June 19th and began to survey the prime landing area, that radar from the Earth suggested would be smooth, to land on the day of the Bicentennial. However, images from orbit showed too many obstructions, so another area was surveyed. The mission planners from JPL found a spot and sent the Viking lander down to land on Mars on another historic date, July 20, 1976, the 7th anniversary of the Apollo 11 landing on the Moon.

The astronomical event times given are for the Traverse City/Interlochen area of Michigan (EDT, UT – 4 hours). They may be different for your location.


Model of the Viking lander

Model of the Viking lander. Credit NASA/JPL.

First Mars image from Viking 1

The first Mars image from the Viking 1 lander, taken moments after touchdown. The Viking landers used rockets to land, after a parachute descent, because the parachutes would not slow the lander enough in the thin Martian atmosphere. The reason to photograph the landing pad was to see how far it would sink into the surface. Credit NASA/JPL.

NASA did finally make a historic landing on July 4th,

the Mars Pathfinder mission, with the first rover to operate on Mars, the Sojourner rover, landed on July 4, 1997. It was a microwave sized rover. The mission on the surface lasted 85 days.


Pathfinder collage, Left to right, the collapsed Sojourner rover attached to one of the lander’s tetrahedron petals; 24 inflated airbags, attached 6 to a side of the Pathfinder tetrahedron; launch of the Delta II rocket carrying Pathfinder to Mars. Credit NASA/JPL.

Sojourner rover investigates Yogi

Sojourner rover investigates a rock named Yogi with its Alpha Particle X-ray Spectrometer to determine its composition. Credit NASA/JPL.

Pathfinder Lander from Sojourner

The Pathfinder Lander/Base Station and its deflated airbags from Sojourner. All communications from Sojourner to Earth is relayed through the Base Station. Credit NASA/JPL.

%d bloggers like this: