Astronomy Picture of the Day
    


Perihelion to Aphelion
<< Yesterday 8.07.2021 Tomorrow >>
Perihelion to Aphelion
Credit & Copyright: Richard Jaworski
Explanation: Aphelion for 2021 occurred on July 5th. That's the point in Earth's elliptical orbit when it is farthest from the Sun. Of course, the distance from the Sun doesn't determine the seasons. Those are governed by the tilt of Earth's axis of rotation, so July is still summer in the north and winter in the southern hemisphere. But it does mean that on July 5 the Sun was at its smallest apparent size when viewed from planet Earth. This composite neatly compares two pictures of the Sun, both taken with the same telescope and camera. The left half was captured close to the date of the 2021 perihelion (January 2), the closest point in Earth's orbit. The right was recorded just before the aphelion in 2021. Otherwise difficult to notice, the change in the Sun's apparent diameter between perihelion and aphelion amounts to a little over 3 percent.

January
February
March
April
May
June
July
August
September
October
November
December
 < July 2021  >
Mo Tu We Th Fr Sa Su



1234
567891011
12131415161718
19202122232425
262728293031
Authors & editors: Robert Nemiroff (MTU) & Jerry Bonnell (USRA)
NASA Web Site Statements, Warnings, and Disclaimers
NASA Official: Jay Norris. Specific rights apply.
A service of: LHEA at NASA / GSFC
& Michigan Tech. U.

Based on Astronomy Picture Of the Day

Publications with keywords: perihelion
Publications with words: perihelion
See also:
All publications on this topic >>