The Solar Impulse 2 airplane, powered solely by the sun, flew very close to Malta a few hours ago, and issued a issued a cheery Hi.

The plane took off from Seville yesterday and is now approaching Cairo, on the last stages of its round-the-world journey.

The current flight is solar plane's penultimate before it reaches the finish line of its round-the-world trip in Abu-Dhabi, the starting point of the journey.

The plane's round-the-world trip, which has been shared by Swiss aviators Andre Borschberg and Bertrand Piccard. 

The flight to Cairo International Airport is expected to take 50 hours and 30 minutes.

With a cruising speed of around 70 kilometres an hour (43 miles per hour), similar to an average car, the plane has more than 17,0000 solar cells built in to wings with a span bigger than that of a Boeing 747.