Admin Table of Contents
What color shift occurs when an object is moving closer to Earth?
Visible light is a spectrum of colors, which is clear to anyone who has looked at a rainbow. When an object moves away from us, the light is shifted to the red end of the spectrum, as its wavelengths get longer. If an object moves closer, the light moves to the blue end of the spectrum, as its wavelengths get shorter.
How can we find out if a star is moving?
Here’s the game: if a star is coming towards you, its Fraunhofer lines will move toward the blue end of the spectrum (“rainbow”). If a star is moving away from us, its Fraunhofer lines will move towards the red end of the spectrum.
Are blue stars moving towards us?
But although the Universe is expanding, not all objects are redshifted. Some of the nearest stars, such as Barnard’s Star, are moving towards us and hence show a ‘blueshift’ (their light is shifted towards shorter wavelengths). Even some galaxies (for example, the Andromeda Galaxy) are blueshifted.
Why are the planets moving away from each other?
But the answer is: it depends. The speed the planets are moving away from each other would be the biggest factor, since the gravity of both would pull them closer, according to Newton’s Law of Gravitation: F (g) = G (m1*m2)/r^ 2. F (g) would be the force pulling each one closer to the other.
How to compare the size of different planets?
2. Have students gather data and compare planet sizes. Divide students into small groups. Distribute one copy of the worksheet Planetary Size Comparison to each group. Have groups use the Planet Size Comparison interactive to find and record data on planet diameters and ratios. Ask:
Can a planet pass close to another planet?
All eight of our planets are expected to remain in their orbits, stably, for as long as the Sun remains a normal, main sequence star. But this isn’t necessarily the case for all Solar Systems. If two planets pass closely by one another in orbit, one can perturb the other, resulting in a massive orbital change.
What is the closest two planets can come near each other?
If you mean what is the closest two objects could come without tearing each other apart, it is the Roche limit as explained by jherico. If you mean the closest two planets ever come our actual solar system, than its about 24 million miles on Venus’ closest approach to Earth.