Solar System
The following movies are available showing various solar system simulations. Image quality is greatly superior when running simulations from within AstroGrav.
- The Moon in 2016
- The Long-Term Fate of Encke's Comet
- The Path of Mars in 2013 and 2014
- The Phases of Venus between 2010 and 2020
- The Inner Solar System Viewed From Pallas
- The Inner Solar System Viewed From Pallas (3D)
- Solar Analemma
The Moon in 2016
An AstroGrav video that shows a simulation of the changing the size and phase of the Moon in the year 2016, as seen from the Earth. The glow from the Sun can be seen flashing past during some of the new moons.
You can download the simulation file itself from the AstroGrav website, run it with AstroGrav, and edit and experiment with it as you wish. You will need AstroGrav 3.2 or better to use this simulation, and might need to change the time step in the evolution settings in order to get the simulation to run at an acceptable speed.
The Long-Term Fate of Encke's Comet
An AstroGrav video that shows a simulation of the long-term fate of Comet 2P/Encke. As time passes, the gravitational influence of the planets causes the comet's eccentricity to get bigger and bigger. As a consequence, its perihelion distance becomes smaller and smaller, until it eventually becomes less than the Sun's radius and it collides with the Sun. In this simulation, this happens around AD 75,000. However, the orbit of Encke's comet is highly chaotic, and tiny changes in the initial state of the system can shift the time of collision by thousands of years. Because of this, it is not possible to predict the time of collision with any accuracy.
The names of the brighter background stars are shown, and their motion is clearly visible over this long period of time.
You can download the simulation file itself, run it with AstroGrav, and edit and experiment with it as you wish. You will need AstroGrav 2.1.2 or better to use this simulation.
The Path of Mars in 2013 and 2014
An AstroGrav simulation that shows the path of Mars amongst the stars and constellations, as seen from the Earth in the years 2013 and 2014. Mars is considerably brighter between late February and late May 2014, when it performs the retrograde loop as the Earth overtakes Mars. The Sun and other planets are visible at some stages of the simulation.
You can download the simulation file itself, run it with AstroGrav, and edit and experiment with it as you wish. You will need AstroGrav 2.1.2 or better to use this simulation.
The Phases of Venus between 2010 and 2020
This AstroGrav video shows the changes in the size and phase of the planet Venus, as seen from the Earth between the years 2010 and 2020. Each second of the video represents the passage of 80 days. The flash seen at each inferior conjunction (when Venus is at its largest) and at each superior conjunction (when Venus is at its smallest) is the glow from the nearby Sun.
You can download the simulation file itself, run it with AstroGrav, and edit and experiment with it as you wish. You will need AstroGrav 2.1.2 or better to use this simulation.
The Inner Solar System Viewed From Pallas
An AstroGrav simulation that shows the planets of the inner solar system as viewed from the asteroid Pallas. For a large asteroid, Pallas has a large inclination (35 degrees) to the plane of the solar system, giving it a view of the inner solar system from above and below at different parts of its orbit.
[Note: There is an error in the date shown in this simulation. 'Jan 01' should be 'Feb 01', and every date shown should have 31 days added to it to get the real date.]
You can download the simulation file itself, run it with AstroGrav, and edit and experiment with it as you wish. You will need AstroGrav 2.2.1 or better to use this simulation.
The Inner Solar System Viewed From Pallas (3D)
An AstroGrav simulation that shows in 3D the planets of the inner solar system as viewed from the asteroid Pallas. For a large asteroid, Pallas has a large inclination (35 degrees) to the plane of the solar system, giving it a view of the inner solar system from above and below at different parts of its orbit. The marks on the opposite side of each orbit show the positions of the perihelion (closest to the Sun) and aphelion (farthest to the Sun) of each planet.
To watch this video, 3D glasses with red in the left lens and cyan in the right lens are ideal. However, 3D glasses with green or blue instead of cyan in the right lens will also work.
You can download the simulation file itself, run it with AstroGrav, and edit and experiment with it as you wish. You will need AstroGrav 2.2.1 or better to use this simulation.
Solar Analemma
An AstroGrav simulation that shows a solar analemma, together with the corresponding paths for Mercury and Venus over a five year period. These curves are the paths formed by the motions of the objects at one day intervals when viewed from a particular location at local noon. The Sun's analemma repeats annually, whereas the paths of Mercury and Venus are irregular.
The video covers a period of five years at a rate of about one month per second. The Moon can be seen flashing from right to left about once a second, and the outer planets are visible moving slowly from left to right at certain times.
Reykjavik was chosen as the viewpoint because its northerly location allows the horizon, Sun's analemma, and paths of Mercury and Venus to all be visible without using too high a field of view.
You can download the simulation file itself, run it with AstroGrav, and edit and experiment with it as you wish. For example, the viewpoint can easily be changed to anywhere in the world, and the time can be changed to any desired time of the day. You will need AstroGrav 3.0 or better to use this simulation.