Washington, Aug 6 (IANS): A string of tweets on behalf of US space agency Nasa's rover Curiosity tracks the tense moments before the spacecraft landed on Mars.

"I'm safely on the surface of Mars. GALE CRATER I AM IN YOU!!!," said an ecstatic tweet after the rover landed safely on Mars.

Moments earlier, another tweet said: "Backshell separation. It's just you & me now, descent stage. Engage all retrorockets!"

The critical tweets began with the one saying: "Guided entry is begun. Here I go!".

Less than a minute later, another said: "Parachute deployed! Velocity 900 mph. Altitude 7 miles. 4 minutes to Mars!".

And then it said: "Heatshield separation. Next up: Radar must lock on ground."

Soon after landing on Mars, the rover beamed its first photograph which showed a shadow of the rover on the red planet.

"It once was one small step... now it's six big wheels. Here's a look at one of them on the soil of Mars," added a tweet that referred to astronaut Neil Armstrong's famous words "one small step for man, one giant leap for mankind" after he set foot on moon.