Basics Flashcards
What are angles in Astronomy measured in?
Degrees, minutes, and seconds of arc
What do our eyes detect?
The angular size of objects or the angular distance between two objects.
What is the distance estimated by?
The stereoscopic effect
What do small angles measure the ratio of?
Width against Distance
What sets the limit on how well you can distinguish close together objects?
The receptor cells at the back of the eye.
Mercury facts?
Year: 87.97 days
Magnetic field
Almost no atmosphere
Temp:-150 to 450
Venus facts?
Year: 224.7 days
The morning and evening star
Green house effect
Temp: 464
Earth facts?
Year: 365.26 days
Water on surface
Magnetic field
Atmosphere
Temp: 10-20
1 moon
Mars facts?
Year: 1.881 Earth years
Frozen water
Has seasons
Low pressure CO2 atmosphere
Temp: -140-20
Jupiter facts?
Year: 11.86 Earth years
Giant magnetic field
Emits more energy than it receives
Atmosphere mostly of H2 and Helium
Moons: 92+
Saturn facts?
Year: 29.46 Earth years
Ringed planets
Magnetic field
Atmosphere mostly of Helium and H2
Emits more energy than it receives
Moons: 83
Uranus facts?
Year: 84.01 Earth years
Almost features atmosphere
Greater tilt of axis
water, ammonia, methane
Moons: 27
Neptune facts?
Blue because of methane
Jupiter like atmosphere
Unexplained internal heat
Moons:14 moons ( largest, Triton, with retrograde revolution)
Pluto facts?
Year: 247.7 Earth years
Dwarf planet since 2006
Eccentric orbit
Temp: -223
Moons: 5
What is the Kuiper belt?
Many Pluto-like bodies, pluto included, short-period comets.
What is the Oort cloud?
Hypothesized spherical cloud of objects, source of long-period comets.
What is the purpose of a telescope?
To increase the angular size of the object as compared when observed by the naked eye.
What does a longer focal length mean?
The larger the magnification
The bigger the lens, the …
More light collected
What are the telescope types and do they require maintenance?
Refracting, no. Reflecting, yes.
What are the conditions for good observation?
Dry: No distortion of light due to water particles
Unheated surroundings: To avoid atmospheric shimmer of the image caused by rising heat from the telescope room.
Low-density atmosphere: To avoid blurring of the image. So, you need high altitudes.
What is the James Webb telescope looking at?
Infrared light from first stars and galaxies in the universe.
Detailed atmospheric characterization of potentially habitable exoplanets.
What does the ELT wide field allow for?
Retrospective Astronomy
What is an AU a measure of?
The distance between the Earth and the Sun
