Kepler Discovers How Planets Move
13.09.1997

Johannes Kepler used simple mathematics to describe how planets move. Kepler was an assistant to the most accurate astronomical observer of the time, Tycho Brahe. Kepler was able to use Brahe's data...

Morning, Planets, Moon, and Montreal
20.03.2020

Dawn's early light came to Montreal, northern planet Earth, on March 18, the day before the vernal equinox. At the end of that nearly equal night the Moon stands above a dense constellation of urban lights in this serene city and skyscape. Of course the Moon's waning crescent faces toward the rising Sun.

Moon, Mars, Saturn, Jupiter, Milk Way
20.05.2020

It is not a coincidence that planets line up. That's because all of the planets orbit the Sun in (nearly) a single sheet called the plane of the ecliptic. When viewed from inside that plane -- as Earth dwellers are likely to do -- the planets all appear confined to a single band.

Planetary Alignment over Italy
19.12.2021

It is not a coincidence that planets line up. That's because all of the planets orbit the Sun in (nearly) a single sheet called the plane of the ecliptic. When viewed from inside that plane -- as Earth dwellers are likely to do -- the planets all appear confined to a single band.

APOD: 2023 January 2 Б After Sunset Planet Parade
2.01.2023

Look up tonight and see a whole bunch of planets. Just after sunset, looking west, planets Venus, Saturn, Jupiter and Mars will all be simultaneously visible. Listed west to east, this planetary lineup will have Venus nearest the horizon, but setting shortly after the Sun.

Three Planets and a Comet
23.12.2021

Are you still looking for that perfect holiday gift for an astronomer? If your night sky is dark and horizon clear enough, the Solar System may have done your shopping for you. Send them outside after sunset to see three planets and a comet.

An Evening Sky Full of Planets
11.01.2025

Only Mercury is missing from a Solar System parade of planets in this early evening skyscape. Rising nearly opposite the Sun, bright Mars is at the far left. The other naked-eye planets Jupiter, Saturn...

Conjunction Over Reunion Island
7.03.2012

You don't have to be on Reunion Island to see this week's planetary conjunction. Only if you want to see this picturesque seascape as well. To see the conjunction from just about anywhere in the world, look to the west after sunset.

Kenya Morning Moon, Planets and Taurid
12.11.2015

On November 8, a waning crescent Moon joined the continuing parade of planets in Earth's morning skies. Captured here from Amboseli National Park, Kenya, even the overexposed moonlight can't washout brilliant Venus though, lined up near the ecliptic plane with faint Mars and bright Jupiter above.

A Five Planet Dawn
30.01.2016

As January closes and in the coming days of February, early morning risers can spot the five naked-eye planets before dawn. Though some might claim to see six planets, in this seaside panoramic view all five celestial wanderers were found above the horizon along with a bright waning gibbous Moon on January 27.