Astronomy non mtah questions

What is the meridian?

The arc that runs from North to South through the point directly overhead

When the moon appears to completely cover the Sun (a solar eclipse), which phase must the moon be in?

The new moon phase.

If I am swinging a ball on the end of a string and then shorten the string so that the circular motion of the ball has a smaller radius, conversation of angular momentum indicates that

the angular speed of the ball will increase.

If you could see the stars during the day, the drawing above shows what the sky would look like at noon on a given day. In the drawing, the Sun is near the constellation Gemini. Near which constellation would you expect the Sun to be located at Sunrise?

Gemini

What is absolute Zero, the zero point of the kelvin temperature scale

is the theoretical temperature at which all molecular motion stops, defined as 0 K or -273.15 °C.

Imagine that Earth’s orbit is changed to be a perfect circle around the Sun, so that Earth’s distance to the Sun never changed. How would this affect the seasons?

We would continue to experience the seasons in essentially the same way we do now

Which os the following electromagnetic waves has the longest wavelength

Radiowave

For the same 500kg sports car and 2000kg truck in the same scenario above, the acceleration experienced by the sports car is?

four times as large as that experinced by the truck

In astronomy what do we mean by a blackbody

A blackbody is a body that absorbs all form of light heat

Galileo made several important discoveries that contributed to the development of the heliocentric model, what is the first one?

Mountains on the moon

Galileo made several important discoveries that contributed to the development of the heliocentric model, what is the second one?

The largest moons of Jupiter

Galileo made several important discoveries that contributed to the development of the heliocentric model, what is the thrid one?

Venus goes through a full cycle of phases

What is a spectral absorption line

A spectral absorption line is a dark band in a spectrum created when atoms absorb photons of specific energies

From Earth, Solar eclipses, when the Moon blocks the light from the Sun, are usually separated by about six months. Why is this?

or us to see an eclipse Earth, the Moon and the Sun need to be perfectly lined up and the orbit of the Moon is inclined relative to the orbit of Earth

Kepler’s second law states, “a line joining a planet and the Sun sweeps out equal areas during equal intervals of time.” For a planet with an elliptical orbit what does this mean for the speed of its orbital motion as it gets further from the Sun?

The planet will move slower as it gets further from the Sun

A toaster has several metal coils that heat up to toast the bread. When they are cold, these coils are a dull black. Describe what you would expect to see if you watch the coils as they heat up.

As the coils heat up you will see them start to glow a faint red. As they continue to heat up the colour will change becoming more orange and the glow will also get brighter.

The lens shown in the diagram at left above is suffering from a type of aberration, causing light entering the lens at different distances from the centre of the lens to be focussed at different distances behind the lens. This results in a point source producing an image like the one shown at the right. Which type of aberration is this lens suffering from?

Spherical aberration

We see a large number of objects, like Pluto, that have orbital resonances with Neptune, such that there is an integer ratio between their orbital period and that of Neptune. For Pluto this ratio is 3:2, so Pluto orbits the Sun exactly twice for every three orbits of Neptune. The existence of these resonant objects is evidence that:

Neptune migrated outwards early in Solar System history

The most common type of exoplanet that we have discovered so far is:

Super-Earths

Chromatic aberration is a type of optical aberration that can degrade the quality of images produced by telescopes. It is caused by:

Light of different wavelengths having different focal lengths.

The following bodies are listed in order from largest to smallest: Venus, Mars, Mercury, the Moon, Ceres. Which one would we expect to have cooled the fastest?

Ceres, the smaller the body, the faster it cools

The greenhouse effect increases the surface temperature of a planet through:

The absorption of infrared radiation by molecules like CO2 and H2O

An earthquake occurs at the location shown in the diagram. At which of the seismograph stations would P-waves be detected?

All of the stations

Looking at the diagram in the previous question again, at which of the seismograph stations would S-waves be detected?

Seismograph stations A and D

For a planet to generate a magnetic field, it must have a fluid layer that is:

Rotating fast enough

When a planet passes in front of its host star we call this a:

Transit

What is the difference between a meteor and a meteorite?

A meteor is the bright streak we see in the sky as something enters our atmosphere, while a meteorite is the solid fragment of an impacting object that we can pick up off the ground afterwards.

What are two advantages of putting a telescope in orbit, example 1

A telescope in space is not affected by light pollution.

What are two advantages of putting a telescope in orbit, example 2

A telescope in space is not affected by the distortions introduced by Earth’s atmosphere.

What are two advantages of putting a telescope in orbit, example 3

A telescope in space can detect wavelengths of light that are blocked by Earth’s atmosphere.

All of the terrestrial planets originally had a primary atmosphere composed mostly of hydrogen and helium. This primary atmosphere is later lost. Why is this?

Hydrogen and helium are very light gases that can easily escape off into space

There are three main methods that we use for detecting exoplanets. Describe how one of them works, and which types of planets this method is best at detecting.

Direct detection looks for light emitted by the planet itself. This is best at detecting young, high mass planets far from their parent star, so that the planet is brighter, and we can more easily distinguish it from the parent star (resolve them as separate objects).

When we look at the Solar System we observe that there is a big difference between the inner Solar System where we find relatively small, rocky planets like Earth, and the outer Solar System where we find large, gas rich planets like Jupiter. What is the reason for this division?

This division is a result of the ice line. Beyond the ice line water would have been solid, meaning there would be more solid material available and planets could grow bigger and faster, producing the giant planets, whereas inside the ice line less material was available, leading to smaller, rocky planets like Earth.

The climate system has both positive feedbacks that tend to amplify the size of changes in global temperatures and negative feedbacks that tend to reduce the size of changes in global temperatures. Give an example of a feedback and explain why it is a positive or negative feedback.

he ice-albedo effect, where highly reflective ice is swapped with much darker water or rock is a positive feedback since as Earth warms, more ice melts, reducing the albedo of Earth and meaning more radiation is absorbed, warming the planet further. Likewise, on a cooling Earth, more ice forms, increasing the albedo and reflecting more radiation, cooling the planet further.