Now, there’s an asteroid twice as much as Dubai’s Burj Khalifa 

Remember the 2014 sci-fi flick Asteroid vs. Earth? Actor Sky Evans had discovered a huge asteroid hurtling towards the earth. It was supposed to hit the earth in 10 days. Well, something similar is going to happen in reality on May 27 this year. According to USA’s space agency, National Aeronautics and Space Administration (NASA), a ‘potentially hazardous asteroid’ called 7335 (1989 JA) is set to fly past Earth on that day. Scientists believe that this large space rock is twice as much as the size of Dubai’s Burj Khalifa. The diameter, they say, is as big as that of Mount Everest: 1.8 km.  

7335 (1989 JA): What type of asteroid is this?  
This new asteroid has been classified as an Apollo class Near-Earth object (NEO) by NASA's Centre for Near-Earth Object Studies (CNEOS), a centre for calculating asteroid and comet trajectories and their chances of colliding with Earth. According to the estimates of NASA, asteroid 7335 (1989 JA) is larger than about 99 per cent of all the NEOs. 

But, what are Apollo class asteroids and NEOS? These are asteroids that orbit the Sun and also cross the orbit of the Earth intermittently. These near-Earth objects derive their names from the 1862 Apollo asteroid, discovered by German astronomer Karl Reinmuth in the 1930s. Till date, astronomers know of about 15,000 such Apollo-class asteroids.  

NEOs are celestial bodies that pass within 30 million miles of our planet's orbit. It is said that 7335 (1989 JA) will whizz past the earth from a distance of four million kilometres. This is more than 10 times the distance between the Earth and the Moon. Also, it will pass by the Earth at a startling speed of roughly 47,200 miles per hour. Can you believe this? It is nearly 20 times faster than a rifle bullet and a fifth of the speed of lightning! 

Why is it a potentially hazardous asteroid (PHA)? 
A potentially hazardous asteroid (PHA) is a near-Earth object, such as an asteroid or a comet with an orbit that allows it to pass close enough to cause substantial regional damage if it collides with the Earth.  

Moreover, PHAs have a minimum orbit intersection distance with Earth of less than 0.05 astronomical units and an absolute magnitude of 22 or brighter. Sounds a little confusing, right? Let’s make it easy for you. So, minimum orbit intersection is a measure used in astronomy to assess potential close approaches and collision risks between astronomical objects. On the other hand, astronomical unit is the distance from the Earth to the Sun and absolute magnitude is used to measure the luminosity of a celestial object.