spacecraft · beyond the heliosphere, interstellar space
Voyager 1
Humanity's most distant spacecraft, first human-made object in interstellar space (2012).
What it is
Spacecraft: Ours. The only things on this list we made. Every kind of thing there is →
Can you see it?
No. No telescope on Earth will show you this one; it is here to be understood, not seen. It is here because it is worth knowing about — and because leaving it out would make the sky look emptier than it is.
Worth knowing about Voyager 1
Voyager 1 is about as wide as a bus is long, once its booms are unfolded. In weight, about as much as a small car. Sunlight takes 24 hours to reach Voyager 1 — and a little longer every day, because it is still heading outwards.
- How it moves
- Racing outward at about 3.5 AU every year.
- The machines we sent
- Launched September 5, 1977 -- took a faster, more direct path and overtook its twin. Flew past Jupiter (1979) and Saturn (1980); during the Jupiter flyby, scientists discovered active volcanoes on the moon Io, the first ever seen anywhere besides Earth.
- What makes it worth knowing
- Left the Sun's protective 'bubble' (the heliosphere) and entered true interstellar space on August 25, 2012 -- the first human-made object ever to do so. Runs on heat from decaying plutonium (an RTG), losing about 4 watts of power every year -- of its original 10 science instruments, only 2 are still switched on today. Carries the Golden Record, a gold-plated disc with greetings in 55 languages, music from around the world, and images of Earth.
Seen next to things you know
The numbers
| Across | 0 km |
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| Distance from the Sun, on average | 25 900 000 000 km (25.9 billion) · sunlight takes 24 hours |
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How anyone knows this
Nobody flew a tape measure out there. Every number on this page was worked out from the ground:
What it belongs to
Then go outside
Not this one. But the sky over your head is full of ones you can see, and the Planetarium knows which.
