NASA has released a virtual flyover of the asteroid 4 Vesta. / NASA JPL
One of the biggest asteroids in our solar system has come so close to Earth that it is visible in the night sky with the naked eye.
The asteroid – known as 4 Vesta, or "Vesta'" – is so big and bright that it can be spotted in despite being 170 million kilometres away.
It is visible in both the northern and southern hemispheres, where it can be seen in the night sky close to Mars, Saturn and the Sagittarius constellation, the Daily Mail reports.
Vesta, one of the largest asteroids in the Solar System, is passing Earth close enough to see. Here its size is given in comparison to the Moon.
But there's no need to panic just yet. Nasa says the asteroid isn't coming any closer to Earth and there is no chance of it hitting our planet.
The asteroid, which measures more than 310 square miles (800,000 square kilometres) in size – 50 times wider than the meteor that wiped out the dinosaurs, will be visible in the night sky until July 16.
Vesta is named after the goddess of the hearth and household in Roman mythology.
The rock, one of the largest known to mankind, currently resides in the asteroid belt.
From Earth, the immense asteroid – which measures three times the size of New Zealand– will appear in the night sky as a dim yellow dot.
The asteroid is easy to spot compared to other space rocks in the same belt as its surface reflects more light than the moon.
To stargazers in the northern hemisphere, Vesta will appear beyond the northwest tip of the Sagittarius constellation.
As NASA's Dawn spacecraft takes off for its next destination, this mosaic synthesizes some of the best views the spacecraft had of the giant asteroid Vesta. Photo / Getty Images
Saturn and Mars will be nearby, with all visible to the naked eye from now until mid-July.
For those in the southern hemisphere, the mirror image is true – with the asteroid appearing south-westerly of the constellation.
The last time the asteroid was visible in the night sky was 2011.
Vesta is the second largest chunk of rock orbiting in the asteroid belt, with Ceres being larger.
The latter was recently reclassified as a dwarf planet.
The asteroid belt is a ring of space debris that orbits around the sun and resides between Mars and Jupiter.
Most recently, Vesta came closer to our planet than it has in 20 years.
The surface of the asteroid is filled with craters, similar to our moon, which are believed to have been caused by a large collision in the rock's formative years.
The largest creator spans 285 miles (460 km) in diameter.
It was explored in unprecedented detail by a Nasa mission, known as Dawn, which reached the asteroid in 2012.
After launching in 2007, Dawn explored both Ceres and Vesta as part of a £337 million ($654 million) Nasa project.
After several years of space flight to reach the distant objects, Dawn discovered that Vesta had a surprising amount of hydrogen on its surface.
It also found bright, reflective regions that may have been left over from its birth.
"Our analysis finds this bright material originates from Vesta and has undergone little change since the formation of Vesta over 4 billion years ago," said Jian-Yang Li, a Dawn participating scientist at the University of Maryland, College Park.
Vesta is also known for having one of the tallest peaks ever seen by humans, a 13-mile (21-kilometre) high mountain that stands on its south pole.
The topography of the northern and southern hemispheres of the giant asteroid Vesta, updated with pictures obtained during Dawn's last look back. Photo / Getty Images
"The south polar mountain is larger than the big island of Hawaii, the largest mountain on Earth, as measured from the ocean floor," Dawn principle investigator Chris Russell was reported saying at a conference.
"It is almost as high as the highest mountain in the solar system, the shield volcano Olympus Mons on Mars.'"
Olympus Mons soars about 15 miles (24 kilometres) above the surface of the red planet.
For reference, Earth's tallest peak, Mount Everest, is a mere 5.5 miles (8.8 km) tall.
Vesta was first discovered in 1807 and was named after the Roman goddess of the hearth and household, who is sister to Ceres – the largest asteroid in the belt, which measures 280 square miles more than Vesta.
