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This date in science: Wright brothers’ first flight

The Wright brothers' airplane on its first powered flight on December 17, 1903.  Via Library of Congress.

The Wright brothers’ airplane on its first powered flight on December 17, 1903. Via Library of Congress.

December 17, 1903. On this date, two Ohio brothers – Wilbur and Orville Wright – made the first bonafide, manned, controlled, heavier-than-air flight. It was the first airplane, and it took off at 10:35 a.m. with Orville Wright on board as pilot. He flew their vehicle, called the Flyer, for 12 seconds over 120 feet (about 37 meters) of sandy ground just outside Kitty Hawk, North Carolina.

December 2014 guide to the five visible planets

Skywatcher, moon, planet (looks like Venus) from Predrag Agatonovic.

Skywatcher, moon, planet from Predrag Agatonovic.

In December, 2014, Venus out briefly after sunset; Mars up the early evening; Jupiter shines from mid-to-late-evening to dawn; Saturn in the southeast predawn; Mercury lost in the sun’s glare.

See a star that changes its brightness

Artist’s concept of the star Sheliak, or Beta Lyrae. It’s really two stars that eclipse each other as seen from our earthly vantage point. Image via Fahad Sulehria at novacelestia.com.

Tonight, we zoom in on a variable star – a star whose brightness changes – near the bright star Vega in the small but distinctive constellation Lyra the Harp.

So long, Venus Express!

Visualisation of Venus Express during the aerobraking maneuver, which lasted from which lasted from June 18 to July 11.   During this time, the spacecraft was orbiting above Venus' thick atmosphere at an altitude of around 130 km (about 80 miles).

Visualization of Venus Express during the aerobraking maneuver, which lasted from which lasted from June 18 to July 11, 2014.

ESA announced today (December 16) that it has officially declared an end to the eight-year mission of the Venus Express spacecraft. It lost full contact with Venus Express on November 28, and the spacecraft is expected to fall into Venus’ thick atmosphere and likely be destroyed in the coming weeks.

Questions of life on Mars revive with methane spike

The first definitive detection of Martian organic chemicals in material on the surface of Mars came from analysis by NASA's Curiosity Mars rover of sample powder from this mudstone target,

A drill hole on Mars. The robot rover Curiosity detected a temporary spike in methane in the air around itself, and it detected different Martian organic chemicals in a Martian rock. Image via NASA/JPL-Caltech/MSSS

The mystery of whether Mars has or ever had life got a boost today (December 16, 2014) when NASA announced that its Curiosity rover – which landed on Mars in August, 2012 – has measured a tenfold spike in methane in the atmosphere around the rover.

Why does Earth have four seasons?

Low sun at winter solstice

Low sun at winter solstice

Many believe Earth’s changing distance from the sun causes the change in the seasons. But that is not the case.

Everything you need to know: Quadrantid meteor shower

From mid-northern latitudes, the radiant point for the Quadrantid shower doesn’t climb over the horizon until after midnight.

The 2015 Quadrantid meteor shower is likely to produce the most meteors before dawn January 4, although in the glare of the almost-full moon.

Hawaii’s Waimea Canyon

Photo credit: Chris Tinker

Photo credit: Chris Tinker

Known as the Grand Canyon of the Pacific. Photo by Chris Tinker.

Constellation Virgo represents a Maiden

2014-dec-16-moon-spica-night-sky-chart

Yes, we’re still talking about the predawn sky. Tomorrow we’ll shift into to evening sky. I can’t resist showing you these crescent moons in the east before dawn, during the part of each month when you’ll find them there. Tomorrow morning – December 17, 2014 – the bright star near the moon is Spica in the constellation Virgo.

How birds get by without external ears

Photo credit: Mr. TinDC/Flickr

Photo credit: Mr. TinDC/Flickr

Unlike mammals, birds have no external ears. The outer ears of mammals help the animal identify sounds coming from different elevations. Mammals’ ears absorb, reflect or diffract the sound waves because of their special structure. But birds are also able to perceive whether the source of a sound is above them, below them, or at the same level. How do they do it?