Standard Candles - Measuring Cosmic Distances:

Among the various questions we are often asked about, the one that comes to the forefront of the mind deals with how we accurately estimate how distant objects truly are from us. It"s a difficult task all together since humans are inherently incapable of truly grasping how large the distance that separates the sun from Pluto or the Oort cloud is (not to mention our crappy depth perception) -- let alone trying to wrap your mind around the 4.37 light-year gap separating our solar system and its closest neighbors in the Alpha Centauri system. Then, we must contemplate the vastness of the universe outside of our peripheral view.. like, all of the planetary systems across our galaxy at large and of our local group -- a region of space containing more than 54 galaxies. We know that much more exists beyond our local group, which brings us to the point of this article... how exactly are distances measured? Lets take a look:

First up, Cepheid variable stars: http://www.fromquarkstoquasars.com/measuring-cosmic-distances/

Image Credit: NASA/JPL/Cal-tech

Astronomy Picture of the Day: 01/04/14 - The Fireworks Galaxy

To start off 2014 right, this is the Fireworks Galaxy, aptly named given its brilliance. NGC 6946, as it is formally known as, lies about 10 million light-years from Earth in the constellation of Cepheus. When it was originally discovered by Sir William Herschel, the galaxy was widely believed to be a member of our local group, which is made up of over 50 galaxies, including several other dwarf-galaxies. It wasn"t until years later that astronomers discovered that the reddening seen enveloping the galaxy was from interstellar dust grains, obscuring our view (instead of red-shift).

Speaking of red, the applicable areas are star forming regions, teeming with new-life -- while the blue bits are actually celestial members of our own galaxy, which are obstructing our view of NGC 6946. Interestingly, several new supernova remnants have been discovered each year for the last 60 lurking within NGC 6946"s spiral arms. This is very unusual, as it is normal to only witness one supernova blast every 30 years in galaxies similar to our own.

References & Further Reading: http://www.fromquarkstoquasars.com/apod-fireworks-galaxy/

Image Credit: NASA/JPL-Caltech/R. Kennicutt (U. of Ariz./Inst. of Astr., U. of Cambridge) and the SINGS Team

Tonight, Meteors will light up the winter sky:

If you"re in the Northern Hemisphere, you"re in luck! Tonight, turn your eyes towards the Big Dipper"s handle and look to the west of the bright star Arcturus. If the weather is favorable (and light pollution isn"t clouding the skies and obscuring your view), then you should be able to see some 80-200 meteors per an hour streaking through the sky. If you"ve never seen a meteor shower before, be sure to check it out this evening starting at midnight and carrying on until dawn. They are truly glorious events, and definitely worth a little lost shut-eye.

These meteors will blast into Earth"s atmosphere at about 90,000 miles per hour (144,800 km/h), but you"ve no need to fear any deadly cataclysms. The typical bright meteor is produced by a particle with a mass less than 1 gram...no larger than a pea. So even if the Quadrantids set the sky aglow, you"ve nothing to fear.

Want to learn more amazing facts about meteors and how to find them? See:
http://www.fromquarkstoquasars.com/tonight-meteors-will-light-up-the-winter-sky/

Image via
http://www.flickr.com/photos/73449134@N04/8343003942/in/photolist-dHf5py-dH9EGv-dH6aWh-97BHji-b7byEF-b7byVX

New Observation of a Coronal Mass Ejection:

Coronal mass ejections (CMEs) are quite possibly the most terrifying storms in the solar system (yes, even more horrifying than Jupiter"s Great Red Spot). Imagine an explosion that sends 100 billion kg (220 billion pounds) of superheated material storming towards you at speeds reaching 1000 km/second (2 million mph). That"s essentially what coronal mass ejections are. These events can release as much energy as one billion hydrogen bombs.

In short, these solar events are amazingly powerful and amazingly destructive. And we had an opportunity to witness one of these events recently, on December 16th and 17th.

See more images of this CME, as well as a video, at:
http://www.fromquarkstoquasars.com/new-observation-of-a-coronal-mass-ejection/

Via:
NASA

Nature At Its Most Devastating: The Science Of Earthquakes

Earthquakes are often amazingly impressive events. If they are large enough, they can disrupt local habitats and even alter Earth"s rotation. Just a few centuries ago, we could only explain volcanic and seismic activities as the acts of gods who were punishing their creations. For example, ancient Greeks believed that Poseidon was the "Earth-Shaker," a being who would topple their cities if they didn"t worship and appease him. Unfortunately for them, Greece sits in one the most earthquake prone areas of the world, situated in a boundary region between 3 tectonic plates (their God must have often appeared to be displeased). Similarly, the Romans believed the Italian island of Volcano was the vent above the forge of the god Vulcan.

Centuries later, even with all our technological advances, we haven"t come to a complete understanding of the various phenomena that make up Mother Nature. Nevertheless, today, scientists have a very reliable and accurate understanding of the mechanics behind these (often devastating) seismic events.

To learn about these fantastic events, see:
http://www.fromquarkstoquasars.com/nature-at-its-most-devastating-the-science-of-earthquakes/

In this image:
Smoke engulfs San Francisco as fires erupt after the 1906 San Francisco earthquake.
aia A.L. Murat – Corbis

Astronomy Photo of the Day: The Multiwavelength Sun 1/3/2014

Unfortunately, humans can only see light from a very small part of the electromagnetic spectrum. Quite literally, there is a whole universe out there that we can"t see. Fortunately, we have technology to aid us.

This fantastic image of the Sun shows us how our star looks from the visible part of the spectrum to the extreme reaches of the ultraviolet wavelengths. Of course, the light received by our observatories had to be translated into a color that we could see, so this isn"t *actually* what ultraviolet light looks like; however, the image does give us a pretty good idea of how much of our the Sun we can"t see.

Want to know how much of the universe we are missing? See:
http://www.fromquarkstoquasars.com/astronomy-photo-of-the-day-the-multiwavelength-sun-132014/

Image:
NASA

Nature At Its Most Devastating: The Science Of Earthquakes

Earthquakes are often amazingly impressive events. If they are large enough, they can disrupt local habitats and even alter Earth"s rotation. Just a few centuries ago, we could only explain volcanic and seismic activities as the acts of gods who were punishing their creations. For example, ancient Greeks believed that Poseidon was the "Earth-Shaker," a being who would topple their cities if they didn"t worship and appease him. Unfortunately for them, Greece sits in one the most earthquake prone areas of the world, situated in a boundary region between 3 tectonic plates (their God must have often appeared to be displeased). Similarly, the Romans believed the Italian island of Volcano was the vent above the forge of the god Vulcan.

Centuries later, even with all our technological advances, we haven"t come to a complete understanding of the various phenomena that make up Mother Nature. Nevertheless, today, scientists have a very reliable and accurate understanding of the mechanics behind these (often devastating) seismic events.

To learn about these fantastic events, see:
http://www.fromquarkstoquasars.com/nature-at-its-most-devastating-the-science-of-earthquakes/

In this image:
Smoke engulfs San Francisco as fires erupt after the 1906 San Francisco earthquake.
aia A.L. Murat – Corbis