Little Big Earth and the Universe
Let’s talk about size… 😉 How big are the objects floating in our Universe and how big can they get? Starting with a “big” object, our very own Moon… Embark on a tour of space… A tour of our Universe…
The Moon is 3,500 km in diameter. That’s bigger than the ninth planet of our Solar System – Pluto is only 2,400 km.
“Big” Sun and Beyond
The Sun, our star, is 109 times the diameter of Earth.
We use a new unit here the solar radius, 1 R⊙ = 6.955 \times 105 km = 695,500 km.
|Sirius A (brightest star in the sky)||1.711|
|Pollux (giant orange star)||8.8|
|Arcturus (red giant star)||25.4|
|Aldebaran (red giant star)||44.2|
|Rigel (blue supergiant star)||78.9|
|Pistol Star (blue hypergiant star)||306|
|Antares A (red supergiant star)||883|
|Mu Cephei (red supergiant star)||650-1,420|
And the largest known star, VY Canis Majoris red hypergiant 1420 ± 120 R⊙.
This star has a diameter of 2,800,000,000 kilometres. Such a size is impossible to imagine…
A passenger plane flying at 900 km per hour over the surface of such a big object would take 1,100 years to circle around it once!
Not the Centre of the Universe…
And there are a hundred billion galaxies in the vast expanses of the Universe.
We are NOT the centre of the Universe. Far from it! We’re not even the centre of the Galaxy…