They use complicated trigonometry and mathematics.
Astronomers measure the parallax angle of a planet or star to determine its distance from Earth. By observing the apparent shift in position of the object against the background stars as the Earth orbits the Sun, astronomers can calculate the angle and use it to estimate the object's distance.
Parallax is the method that astronomers use to measure the distance from the sun to the earth.
Distance.
With a long measuring tape.
Astronomers use a method called parallax to measure the distance to nearby stars. By observing how a star's position changes when viewed from different points in Earth's orbit around the Sun, astronomers can calculate the star's distance based on the angle of this apparent shift.
Astronomers use parallax to measure the distance to other stars by observing how a star appears to shift its position against the background of more distant stars as the Earth orbits the Sun. By measuring this apparent shift, astronomers can calculate the distance to the star based on the angle of the shift and the known distance between the Earth and the Sun.
Astronomers use the unit of measure "Light Years" to calculate the distance between pretty much anything in the Universe.
Usually light-years, or parsecs.
Astronomers have decided that Pluto does not meet the definition of a planet.
When exploring space, astronomers use astronomical units, (AU) to measure the distance from one object to another. Since every distance from one object in our solar system to another object in our solar system, the distance of a planet from the sun would be measured in astronomical units
Astronomers use luminosity to measure the total amount of energy a star emits in all directions. By knowing a star's luminosity, astronomers can calculate its distance, size, and temperature. Luminosity helps astronomers understand the life cycle of stars and their evolution.
Astronomers think Pluto is a dwarf planet. And they're right.