Enjoying EarthSky? Subscribe.

207,011 subscribers and counting ...

Blogs

Top 3 tips to avoid mosquito bites

Photo credit: João Trindade

Photo credit: João Trindade

Simple things you can do to get fewer mosquito bites this summer.

How to shoot photos of meteors, or shooting stars

View larger. | Geminid meteor in 2012 by Henry Shaw.

Geminid meteor in 2012 by Henry Shaw.

The best viewing time for the Eta Aquarid meteor shower will probably be tomorrow (Tuesday) morning, from about 3:00 a.m. until dawn. If you’re out watching, maybe you want to try to capture a meteor – with your camera? Here’s the equipment you need, and also the steps to follow.

Comet Halley, parent of 2 meteor showers

Comet Halley's position in May, 2016. The view is from the north side of the solar system, whereby the planets orbit the sun in a counterclockwise direction - but Halley's Comet orbits the sun clockwise. Click here for Comet Halley's present position, or if you'd like, change the date to view its position in any chosen year.

Comet Halley’s position in May, 2016. The view is from the north side of the solar system. Although the planets orbit our sun in a counterclockwise direction, Comet Halley orbits clockwise.

The 2 meteor showers spawned by the famous Comet Halley. And a word about Isaac Newton’s Vis-viva equation, his poetic rendition of instantaneous motion.

A pure methane sea on Titan

Sunlight glints off of Titan's northern seas this near-infrared, color mosaic from NASA's Cassini spacecraft. Image credit: NASA/JPL/Univ. Arizona/Univ. Idaho

Sunlight glints off of Titan’s northern seas this near-infrared, color mosaic from NASA’s Cassini spacecraft. Image via NASA/JPL/Univ. Arizona/Univ. Idaho

We knew that Saturn’s moon Titan had seas and lakes of liquid hydrocarbons, but their exact composition was elusive. Now Ligeia Mare – the second-largest of Titan’s seas – has been found to be filled with almost pure methane.

Shortest lunar month of 2016 starts May 6

Simulated view of the cycle of the moon's phases from new moon to new moon. This cycle is known as the lunar month. From the years 1760 to 2200, the longest lunar month was 29 days 19 hours and 58 minutes and the shortest 29 days 6 hours and 34 minutes.

Simulated view of the moon’s phases. The period of time from new moon to new moon is known as the lunar month, lunation or synodic month. From the years 1760 to 2200, the longest lunar month spans 29 days 19 hours and 58 minutes (Dec. 9, 1787 to Jan. 8, 1778) while the shortest lasts for 29 days 6 hours and 34 minutes (June 12 to July 12, 1885).

The shortest lunar month of the year starts with the new moon on May 6, 2016! What is a lunar month? It’s just the duration between successive new moons. It’s also called a lunation or synodic month. Although the lunar month has a mean period of 29.53059 days (29 days 12 hours and 44 minutes), the actual length varies throughout the year. We list the lunar months of 2016 for you, highlighting the shortest and longest lunar months of 2016 inside…

Orbit like a comet, rocky like an asteroid

Artist's impression of the unique object C/2014 S3 (PANSTARRS). Observations with ESO’s Very Large Telescope, and the Canada France Hawai`i Telescope, show that this is the first object to be discovered that is on a long-period cometary orbit, but that has the characteristics of a pristine inner Solar System asteroid. It may provide important clues about how the Solar System formed. Because the object has spent most of its life away from the inner Solar System it suffered very few collisions, and its surface displays few or no craters. As it formed in the same region as the Earth did, it is mostly rocky, and therefore has only very limited cometary activity.

Artist’s concept of the unique object C/2014 S3 (PANSTARRS). Image via ESO/M. Kornmesser.

Astronomers are calling it a Manx comet, for the tailless cat species. They first believed C/2014 S3 (PANSTARRS) was a long-period comet without a tail, but, on studying its light, found that it more closely resembles a rocky asteroid. Now they think this object is an asteroid, formed billions of years ago in the inner solar system and ejected early on to the deep freeze of space in our solar system’s Oort Cloud.

Astronomical events in 2016

View larger. | Meteor over the Montana Rockies by John Ashley.  Photo taken April 21, 2015.

Meteor over the Montana Rockies by John Ashley.

Dates of major moon phases, conjunctions and oppositions of planets, meteor showers and other important dates in 2016, from astronomer Fred Espenak.

Video: Mars and Saturn in 2016

Video of this year’s oppositions of Mars and Saturn, in front of the constellations Libra and Scorpius. Notice Mars appearing larger around its May 22 opposition! Lots more, plus essential links, inside.

Did human limbs evolve from shark gills?

Skeleton of an embryonic bamboo shark, viewed from the underside. Gill arch appendages extend from each side of the head. Directly below them are a pair of fins. Image credit: Andrew Gillis.

Skeleton of an embryonic bamboo shark, viewed from the underside. Gill arch appendages extend from each side of the head. Directly below them are a pair of fins. Image via Andrew Gillis.

The Sonic Hedgehog gene drives embryonic development of mammal limbs and shark gills. Could our limbs have evolved from gills?

Breakthrough Starshot aims for Alpha Centauri

Photo via BreakthroughInitiatives.org.

The dream of traveling to the stars is alive and well. Artist’s concept via BreakthroughInitiatives.org.

Breakthrough Starshot seeks proof of concept for a 100-million-mile-per-hour mission – using light-propelled nanocrafts – to reach the nearest star in 20 years.