Posts by 

Guy Ottewell

Comet C/2021 T4 Lemmon is sweeping through southern skies

Comet C/2021 T4 Lemmon was discovered at Mount Lemmon Observatory in 2021. It's currently in the southern skies and might become bright enough for binoculars.

How many red dwarf stars in nearby space?

Astronomer Guy Ottewell uses 2 charts - showing 2 different volumes of space - to contemplate and question the density of red dwarf stars in our Milky Way.

Artificial intelligence: Thoughts by astronomer Guy Ottewell

Renowned astronomer Guy Ottewell weighs in on artificial intelligence. Plus, apparently what AI says about him isn't accurate.

The Drake Equation and the late planet

Astronomer Guy Ottewell discusses how the recent discovery of a star swallowing a late planet can help refine an estimate for part of the Drake Equation.

The attitude of the Swan and the Northern Cross

Guy Ottewell answers the question: Since the Northern Cross is vertical as it sets in the west, why is it not also vertical as it rises in the east?

How fast is daytime growing? Guy Ottewell explains

How fast is daytime growing? A table in this post shows differences in the time of sunrise as we approach the March equinox.

The 5 petals of Venus and its 8-year cycle

Learn about the 8-year cycle of Venus in our sky and the petals of Venus, a rhythmic motion of Venus when viewed from an Earth-centered perspective.

The green comet: Comet 2022 E3 ZTF

Learn about the trajectory of the green comet - Comet 2022 E3 ZTF - by the renowned astronomer Guy Ottewell. The comet will be closest to Earth on February 2.

Northern autumn ahead. Here’s your equinox sky

Northern autumn arrives on September 22 or 23, 2022, with the equinox. The time and date depend on precisely where you live. Find out more here.

Full and near moon July 13

Learn more - and see charts - related to the July 13, 2022, nearest full moon of 2022 from master chart-maker Guy Ottewell.