The Speed of the Universe
From planetary days so slow you could outwalk them, to the cosmic speed limit. This page explores the fastest objects in the universe.
- 1 -
Rotation of Venus
Speed: 6.52km/h
An image of Venus
Facts:
Venus rotates the slowest of all planets in the Solar System
A single full rotation on Venus takes the equivalent of 243 days on Earth
Venus actually takes longer to rotate on its axis than it does to orbit the Sun!
- 2 -
Rotation of Earth
Speed: 1,600km/h
Facts:
The Earth takes 23 hours and 56 minutes to complete one full rotation on its axis
However, as the position of the Sun moves during our orbit, it takes an extra 4 minutes for the Sun to return to the same point in the sky, bringing the total length to exactly 24 hours
An image of Earth
- 3 -
Orbit of the Moon
Speed: 3,683km/h
An image of the Moon transiting the Earth
Facts:
The Moon travels around the Earth at just over 1 kilometer per second
It travels a total of 2,290,000km, each full orbit, over the course of around 27 days
- 4 -
Orbit of Pluto
Speed: 17,096km/h
Facts:
Pluto travels around 37 billion kilometers during its orbit around the Sun
That is the equivalent of over 15,000 lunar orbits!
An image of Pluto
- 5 -
The International Space Station
Speed: 28,000km/h
A view of the International Space Station over Earth
Facts:
The ISS contains about as much living space as a 6-bedroom house, and weighs 420,000kg
The ISS was assembled in pieces across 42 seperate rocket launches
The ISS completes 16 full orbits of the Earth each day, or one full orbit every 90 minutes
The ISS has been continuiously occupied since November 2000
- 6 -
Rotation of Jupiter
Speed: 43,000km/h
Facts:
Jupiter is the fastest rotating planet in our Solar System
Despite being 11 times the diameter of the Earth, one day on Jupiter lasts just 10 hours
If Earth rotated as fast as Jupiter a day would only take 54 minutes!
An artists depiction of Jupiter
- 7 -
Voyager 1
Speed: 61,500km/h
An artists depiction of Voyager 1 flying through space
Facts:
Voyager 1 is a spacecraft launched in 1977 to explore the outer Solar System
It is the most distant man-made object ever launched into space
It is also the second longest in-use spacecraft in history, having been in active use for over 46 years.
It is surpassed only by its sister ship, Voyager 2, which launched two weeks earlier
- 8 -
Orbit of Earth
Speed: 107,000km/h
Facts:
Earth has the third fastest orbit in the Solar System, completing one orbit every 365.24 days
During the course of a year we travel nearly 1 billion kilometres around the Sun
This equates to 30 kilometres per second, or the diameter of the Earth about once every 7 minutes
Cities of Earth at night
- 9 -
Orbit of Venus
Speed: 126,077km/h
An image of Venus transiting the Sun
Facts:
Venus has the second fastest orbit in the Solar System, completing one orbit every 224.7 Earth days
Due to the slow rotation of Venus, a year is actually shorter than a day!
- 10 -
Orbit of Mercury
Speed: 170,505km/h
Facts:
Mercury has the fastest orbit of any planet in our Solar System, one year takes just 59 Earth days!
If the Moon orbited the Earth as fast as Mercury orbits the Sun, it would circle the entire planet every 14 hours
An image of Mercury
- 11 -
Parker Solar Probe
Speed: 635,266km/h
An artists depiction of the Parker Solar Probe approaching the Sun
Facts:
The Parker Solar Probe is the fastest man-made object every built
The spacecraft was launched in 2018, and was designed to make a number of very close flybys of the Sun
The spacecraft is accelerated by the Suns gravity, which increases in strength as it gets closer
The Parker Solar Probe is expected to make its closest approach in 2025, where it is expected to reach almost 700,000km/h!
- 12 -
Orbit of the Sun
Speed: 828,000km/h
Facts:
Just as the planets orbit around the Sun, the Sun, and by extention the entire solar system, orbits around the Milky Way galaxy
Despite this impressive speed, the Sun takes about 230 million years to complete one orbit of the galaxy!
If the Earth orbited the Sun at that speed a single year would take just over 47 days
An image of the Sun
- 13 -
S2
Speed: 27,540,000km/h
An illustration of S2 as it approaches Sagittarius A
Facts:
S2 is a star which orbits Sagittarius A, the supermassive black hole at the centre of the Milky Way galaxy
As the star makes its closest approach it is accelerated by the gravity of the black hole
S2 made its last close approach of Sagittarius A in May 2018, travelling over 7,500 kilometres per second
This equates to nearly 3% light speed!
- 14 -
PSR J1748-244ad
Speed: 252,000,000km/h
Facts:
PSR J1748-2446ad is a pulsar located 18,000 light years from Earth
A pulsar is a spinning neutron star which emits beams of electromagnetic radiation from both poles. Each time it completes one rotation it sends a pulse of radiation towards the Earth
PSR-J1748-244gad is the fastest pulsar ever discovered, completing 716 rotations every second!
At that speed, the equator is moving at 24% the speed of light!
An image of PSR J1748-244ad
- 15 -
The Speed of Light
Speed: 1,079,252,848km/h
An illustration of light speed
Facts:
The speed of light is the upper speed limit of the universe.
This is the fastest speed at which information can travel, and can only be achieved by massless particles, such as photons
This speed equates to 300,000 kilometres per second, which is fast enough to travel around the equator of the Earth 7.5 times per second!
Despite this, some objects are so far away that they would take billions of years to reach, even travelling at light speed