What if we could build a spaceship capable of leaving the solar system at the speed of light? How long would it take to reach interstellar space?
Despite being small compared to our galaxy, let alone the entire universe, our solar system is vast. To put this into perspective, imagine yourself as a photon emitted by the Sun. It takes about 8 minutes to reach Earth after leaving the Sun’s surface, and around 5 hours to travel from Earth to Pluto. However, the edge of the solar system lies far beyond Pluto’s orbit.
So, where exactly is the edge of the solar system? Well, it’s complicated. Informally, “solar system” often refers to the space out to Neptune, the last planet. However, some scientists extend this boundary to the Oort Cloud, the source of comets. The inner edge of the Oort Cloud could be as close as 1,000 AU (Astronomical Units; 1 AU is the distance from the Earth to the Sun, approximately 93 million miles or 150 million kilometers) from the Sun, while the outer edge is estimated to be around 100,000 AU.
Thus, if we consider the inner edge of the Oort Cloud, it would take a photon emitted by the Sun around 140 hours to reach the edge of the solar system.
Before reaching the Oort Cloud, there’s a region known as the heliopause. The heliopause is the theoretical boundary where the Sun’s solar wind is halted by the interstellar medium-where the solar wind’s strength is no longer sufficient to push back the interstellar wind. Crossing the heliopause is typically marked by a sharp drop in the temperature of charged particles, a change in the direction of the magnetic field, and an increase in galactic cosmic rays.
In May 2012, Voyager 1, the farthest spacecraft from Earth and the most distant human-made object detected a rapid increase in cosmic rays (a 9% increase in one month, following a gradual 25% increase from January 2009 to January 2012), suggesting it was nearing the heliopause. In the fall of 2013, NASA announced that Voyager 1 had crossed the heliopause on August 25, 2012, at a distance of 121 AU (18 billion km) from the Sun. A photon emitted by the Sun would take around 16.5 hours to reach this distance.
It will take Voyager 1 approximately 300 years to reach the inner edge of the Oort Cloud and possibly about 30,000 years to travel beyond it.
Video: Leaving the Solar System at the Speed Of Light
The 45-minute video below, titled “Riding Light,” shows the journey of leaving the Solar System at the speed of light, stopping at Jupiter, the fifth planet in our Solar System. It would be a long, very long video if it showed the entire journey.
Witness the beauty and vastness of the universe as we journey beyond the boundaries of our own little corner of space. Get ready to be amazed by this incredible video of leaving the solar system at the speed of light.
A small detail: The video assumes that all the planets are aligned in the same direction, which of course, is impossible. All eight planets lining up perfectly is completely impossible. For example, all eight planets will line up within 3.6 degrees every 396 billion years (the Universe is 13.8 billion years old). 3.6 degrees is quite a significant deviation considering the immense size of the solar system. The chances are even worse for all eight planets aligning within 1 degree of the sky – this will occur, on average, every 13.4 trillion years. Even 1 degree is a large enough deviation.
If the video above were more than 100,000 years long, it would cover the entire Milky Way at the speed of light. And how big is the observable universe? Imagine a video like that, but 46.508 billion years in length.
Distances of planets, asteroids, and Pluto from the Sun [in light hours and minutes]
Approximately, on average:
- Mercury: 3 minutes and 13 seconds [0.39 AU]
- Venus: 6 minutes [0.72 AU]
- Earth: 8 minutes 20 seconds [1 AU]
- Mars: 12 minutes and 40 seconds [1.52 AU]
- Vesta (the brightest asteroid visible from Earth): 19 minutes and 40 seconds [2.36 AU]
- Ceres (a dwarf planet in the middle main asteroid belt between the orbits of Mars and Jupiter – it was the first asteroid discovered on 1 January 180): 23 Minutes [2.8 AU]
- 10 Hygiea (the fourth-largest asteroid in the Solar System by both volume and mass): 28 minutes and 8 seconds [3.14 AU]
- Jupiter: 43 Minutes 17 seconds [5.2 AU]
- Saturn: 1 Hour 14 minutes 55 seconds [9 AU]
- Uranus: 2 Hours, 46 Minutes and 28 Seconds [20 AU]
- Pluto: 5 Hours, 24 Minutes and 39 Seconds [39 AU]
From the description of the video:
“In our terrestrial view of things, the speed of light seems incredibly fast. But as soon as you view it against the vast distances of the universe, it’s unfortunately very slow. This animation illustrates, in real-time, the journey of a photon of light emitted from the surface of the sun and traveling across a portion of the solar system, from a human perspective.”
“I’ve taken liberties with certain things like the alignment of planets and asteroids, as well as ignoring the laws of relativity concerning what a photon actually “sees” or how time is experienced at the speed of light, but overall I’ve kept the size and distances of all the objects as accurately as possible. I also decided to end the animation just past Jupiter as I wanted to keep the running length below an hour.”
- Design & Animation: Alphonse Swinehart / aswinehart.com
- Music: Steve Reich – “Music for 18 Musicians”
- Performed by: Eighth Blackbird / eighthblackbird.org
Sources
- Solar System, in Perspective on NASA.gov
- Heliosphere on Wikipedia
