Oh my God! What was that? What was the thing that zoomed past Earth? What, it was a 40-yard-wide asteroid, as big as a ten-storey building that passed close by the Earth on Monday?

Well, our Earth could have a close encounter with a gigantic rock that passed by just 60,000 kilometers over the southwest Pacific, in morning at 12:40AM (1344 GMT), the day before yesterday.

Rob McNaught of the Siding Spring Observatory near Coonabarabran, who watches for asteroids with his telescope 250 miles northwest of Sydney, Australia, discovered the Asteroid 2009 DD45 first, but he was able to estimate that it would just miss hitting our planet Earth.

"It's not something to worry about, but something to be aware of," said McNaught of the Australian National University.

McNaught guessed that the Asteroid 2009 DD45 passed within 38,000 miles of Earth. According to BBC, “the gap was just 72,000 km (44,750 miles); a fifth of the distance between our planet and the Moon”.

The Asteroid 2009 DD45 is thought to be 21-47m (68-152ft) long and 30 -50 meters wide. According to McNaught, it could be just less than twice the height of the geostationary satellites. According to BBC, the Asteroid 2009 DD45 belongs to the size range of the “rock that exploded over Siberia in 1908 with the force of 1,000 atomic bombs”.

The Asteroid 2009 DD45 was first reported on Saturday by the NASA funded Siding Spring Observatory, set up in a search for asteroids. The Asteroid was confirmed by the International Astronomical Union's Minor Planet Centre (MPC), which catalogues Solar System objects.

If the Asteroid 2009 DD45 had hit the ocean, it would have caused a lot of damage, potentially a Tsunami. Definitely, a direct hit on Earth could be a devastating natural disaster, but keeping track of asteroids can make a hit "potentially preventable", McNaught stated.

McNaught said,"If discovered in advance and with enough lead time, there is the possibility of pushing it off course, if you have decades of advance warning. If you have only a few days, you can evacuate the area of impact, but there's not a great deal [else] you can do."

According to McNaught, as the Asteroid 2009 DD45 came near our Earth, it was glowing 5000 times brighter than it did on Friday night. The 2009 DD45 asteroid revolves around the sun every 18 months, but its path is not a threat to out planet at least for the next century. So far, the closest recent flying object listed by the MPC is 2004 FU162, which was a small asteroid about 6m (20ft) across, which came within about 6,500km (4,000 miles) of our planet in March 2004.