[The Month's Sky]
[The Observers' Glossary]

[History of Astronomy]
[We Are Stardust]
[Extraterrestrial Life]
[Coordinate Systems]
[The Calendar]
[Gravity]
[Astronomy and Astrology]
[Scale of the Universe]
[The Brightest Stars]
[The Solar System]
[Measuring The Stars]

[Readers' Feedback (Astronomy)]
[Feedback (Calendar)]
[Feedback (Extraterrestrial Life)]

[Language]
[Travel]
[Democracy]
[Eclipses]
[London]
[Astronomy]
[Mathematics]
[Physics]
[Chemistry]
[Football]
[Television]
[Other]

The Scale of the Universe

This is a pair of easy-to-understand scales of the Universe.
Distances are explained using the time taken by a light beam to travel.
Time is explained by condensing the life of the Universe into a single year.

Support this web site
by making a donation

Distance

Light travels at 300,000 kilometres per second (186,000 miles per second).

In one second, a beam of light can travel SEVEN TIMES around the Earth.

This table shows a number of distances to various objects expressed in terms of how long a beam of light takes to travel that distance.

	Astronomical Distance	How Long Light Takes to Travel This Distance
	From Earth to the Moon our natural satellite	1.25 seconds
We have now left the Earth-Moon system where humans have walked
	From Earth to the Sun the centre of our Solar System	8.3 minutes
	From the Sun to Jupiter the largest planet	41 minutes
	From the Sun to Saturn the furthest naked eye planet	85 minutes
	From the Sun to Neptune the furthest of the Sun's major planets	4.2 hours
We have now left the Solar System, the realm of the Sun, where humans have sent probes
	From the Sun to Alpha Centauri the nearest star to us	4.3 years
	From the Sun to Sirius the brightest star in our sky	8.6 years
	From the Sun to 61 Cygni the first star to have its distance measured	11.4 years
	From the Sun to Pollux one of the twin stars in Gemini	33.7 years
	From the Sun to Castor one of the twin stars in Gemini	51.6 years
	From the Sun to Aldebaran the brightest star in Taurus	65.2 years
	From the Sun to Regulus the brightest star in Leo	77.6 years
Distance where the Sun would no longer be visible to naked eye		c 110 years
	From the Sun to Spica the brightest star in Virgo	263 years
	From the Sun to Acrux the brightest star in the Southern Cross	321 years
	From the Sun to the Pleiades the Seven Sisters star cluster in Taurus	c 385 years
	From the Sun to Betelgeux the red star in Orion	429 years
	From the Sun to Polaris the north pole star	432 years
	From the Sun to Antares the brightest star in Scorpius	604 years
	From the Sun to Rigel the blue star in Orion	777 years
	From the Sun to the Orion Nebula the brightest of the nebulae	1,300 years
	From the Sun to Deneb the brightest star in Cygnus, the Swan	2,600 years
	From the Sun to the Crab Nebula remnant of an exploded star in Taurus	6,300 years
	From the Sun to the Double Cluster a star cluster in Perseus	7,200 years
	From the Sun to Omega Centauri the brightest globular star cluster	16,300 years
	From the Sun to M13 the globular star cluster in Hercules	21,000 years
	From the Sun to the Galactic centre the centre of our Galaxy	27,700 years
	Galactic diameter the diameter of our Galaxy	81,500 years
We have now left our Galaxy, our stellar city
	From the Sun to the Magellanic Clouds the nearest external galaxies	160,000 years
	To the Andromeda Galaxy the nearest large galaxy	2,900,000 years
We have now left the region visible with the naked eye
	To UGC 8091 the farthest of the Local Group of galaxies	7,900,000 years
	To M81 spiral galaxy in Ursa Major	12,000,000 years
	To M104 the Sombrero Galaxy	30,000,000 years
	To M87 a spherical galaxy in Virgo	55,000,000 years
Extinction of the dinosaurs		65,000,000 years
	To Perseus Group a group of 500 galaxies in Perseus	190,000,000 years
	To Coma Group a group of 1000 galaxies in Coma Berenices	225,000,000 years
	To Hercules Group a group of galaxies in Hercules	350,000,000 years
	To Boötes Group a group of 150 galaxies in Boötes	1,240,000,000 years
	To 3C273 the first quasar discovered	2,000,000,000 years
	To Q0134+329 typical quasar	4,500,000,000 years
Formation of the Earth and Sun		4,700,000,000 years
	To remotest quasars discovered in 1998	14,000,000,000 years
	Edge of Universe limit of observable Universe	15,000,000,000 years

This is well summarised in Monty Python's Galaxy Song.

Time

This table shows a number of events in the history of the Universe and the Earth. This is expressed as occurring during a calendar year. The calendar year is assumed to be equivalent to 15,000,000,000 real years (which is probably too high a figure for the age of the Universe).

	Event	Calendar Date and Time
	The Big Bang occurs	1st January at Midnight
	Stable atoms form	1st January at 00:24:31
	First stars and galaxies form	around 15th March
	Formation of the Sun	8th September
	Formation of the Earth	12th September
	Formation of the Moon	13th September
	Formation of the Earth's atmosphere	20th September
	Oldest Earth rocks	30th September
	Earliest evidence of life on Earth	1st October
	Oldest known fossils (single celled organisms)	7th October
	Formation of stable continents	20th October
	Formation of extensive shallow seas	1st November
	Oxygen in Earth's atmosphere	10th November
	First multi-cellular life	18th December
	First shellfish and corals	19th December
	First vertebrates (fishes)	20th December
	First land plants	21st December
	First insects	early 22nd December
	First terapods and seed bearing plants	late 22nd December
	First reptiles	23rd December 5:26pm
	First mammal-like reptiles	24th December 4:48pm
	First dinosaurs	26th December 6:26pm
	First mammals (egg-layers and marsupials)	26th December 9:21pm
	First birds	28th December 8:24am
	First flowering plants	28th December 5:10pm
	First placental mammals	29th December 1:36pm
	Extinction of the dinosaurs	30th December 10:02am
	First primates	30th December 4:27pm
	First monkeys	31st December 0:38am
	First apes	31st December 8:49am
	First hominoids	31st December 6:09pm
	First hominids	31st December 9:05pm
	First tool-making man (Homo Habilis)	31st December 11:00pm
	Homo Sapiens	31st December 11:25pm
	Last ice age (maximum extent)	31st December 11:59:22pm
	Ancient Mesopotamia / Writing	31st December 11:59:47pm
	Ancient Egypt / Hinduism	31st December 11:59:50pm
	Ancient China / Judaism	31st December 11:59:53.3pm
	Ancient Greece / Buddhism	31st December 11:59:54.7pm
	Roman Empire / Christianity	31st December 11:59:55.8pm
	Mayan Civilisation / Islam	31st December 11:59:57.0pm
	Islamic and Moorish Empires / Kublai Khan	31st December 11:59:58.4pm
	Ottoman Empire / Galileo	31st December 11:59:59.2pm
	French Revolution / USA Independence	31st December 11:59:59.5pm
	World War I / Albert Einstein	31st December 11:59:59.8pm
	European Union / Space flight	31st December 11:59:59.90pm
	Year 2000 (Gregorian Calendar)	31st December 11:59:59.99pm

Books From Amazon.co.uk and Amazon.com

Software From Amazon.co.uk and Amazon.com

DVDs From Amazon.co.uk and Amazon.com

KryssTal Related Page

A Brief History of Astronomy

How humanity came from Creation Myths to the Inflationary Big Bang. The key stages in our understanding of our place in the cosmos and the people behind them.

The History and Geography of Inventions

This looks at the history of inventions and the various civilisations of the world.

External Link

This link will open in a separate window

The Official Superstring Web Site
An excellent site containing information about superstrings and cosmology.

Secret Worlds: The Universe Within
A series of images from outside the Galaxy to the quarks within the nucleaus of an atom.

Sizes of Planets and Stars
Scale models of the planets, Sun and stars.

To the COSMOS Astronomical Webring Home Page