A Light Year =

  • m
  • miles
  • astronomical units
  • parsecs
  • light-seconds
  • or, the distance light can travel in one year.

A Light Year Calendar

Light travels at approximately 300,000 km per second. This website functions as a day calendar, showing the objects that a beam of light might pass by, when travelling from the sun, in a straight line, for one year (cats not included).

DAY


0

00:03

Mercury

00:06

Venus

00:08

Earth

00:13

Mars

00:20

Vesta

00:23

Ceres

00:26

Hygiea

00:43

Jupiter

01:19

Saturn

02:12

Chariklo

02:40

Uranus

03:03

New Horizons (spacecraft)

04:10

Neptune

05:24

Pluto

05:28

Enter Kuiper Belt

06:00

Haumea

06:21

Makemake

06:37

Exit Kuiper Belt

09:26

Eris

11:05

Heliosheath

13:51

Ceto

16:50

Voyager I (spacecraft)

03:43

Heliopause

07:53

Bow Shock

21:27

TG422 (scattered-disc object)

23:53

Sedna

19:10

OO67 (centaur)

13:45

SQ372 (comet)

07:51

Enter Hills Cloud

12:19

Exit Hills Cloud

18:48

Enter Outer Oort Cloud

365.25

Our light particles have now travelled for a Julian year (365.25 days) and are not even close to reaching the nearest star. The Crab supernova remnant is about 4,000 years away; the Milky Way Galaxy would take 150,000 years to cross; the Andromeda Galaxy is 2.3 million light-years away. Light will have to travel for another 28 billion years to reach the edge of the visible universe.