Measuring Distances in Space
What unit is commonly used to measure distances beyond the Solar System?
light year
What colour are the hottest stars?
blue
In what type of cloud do stars form?
nebula
What type of galaxy is the Milky Way?
barred spiral galaxy
What type of telescope uses mirrors?
reflecting telescope
What is parallax?
the apparent shift in position of an object when viewed from different locations
What is luminosity?
the total energy a star produces each second
What process powers stars?
nuclear fusion
Who discovered galaxies beyond the Milky Way?
Edwin Hubble
Why must X-ray telescopes be placed in space?
Earth’s atmosphere blocks X-rays
What happens to parallax as distance increases?
the parallax angle becomes smaller
What instrument splits light into a spectrum?
spectrograph
What forms after a massive star explodes in a supernova?
neutron star or black hole
What are the four main galaxy types?
elliptical, spiral, lenticular, and irregular
What Canadian robotic system is used on the ISS?
Canadarm2
Why are astronomical units not useful for measuring distances to stars?
because stellar distances are far too large
A star appears dim from Earth but has high luminosity. What explains this?
the star is very far away
List the stages in the life cycle of a low-mass star.
main sequence → red giant → planetary nebula → white dwarf → black dwarf
What evidence shows the Universe is expanding?
Red shift
Name two health effects astronauts experience in microgravity.
muscle loss and bone loss
Explain how triangulation is used to measure stellar distances.
using observations from opposite sides of Earth’s orbit to calculate distance from the parallax angle
Compare apparent magnitude and absolute magnitude
apparent magnitude is brightness seen from Earth, while absolute magnitude compares stars at the same distance
Why do massive stars have shorter lifespans than low-mass stars?
because they use up their fuel much faster
Explain how red shift supports the Big Bang Theory
galaxies moving away from each other shows the Universe began expanding from one point
Explain two major challenges of long-term Mars exploration.
radiation exposure, lack of resources, microgravity effects, fuel requirements, or dust hazards