Earth Vs. Stuff from the Sun

By Nancy Atkinson - October 11, 2011 at 7:16 PM UTC | Solar Astronomy
Prominence-on-10-10-11.jpg

[/caption]

The Sun is big. And comparatively, Earth is a tiny Lilliputian. We've all seen images comparing the size of Earth to the Sun, but here are two images from October 10, 2011 that really bring home the size-scale of features on the Sun when compared to the size of Earth. Amateur astronomer Ron Cottrell from Oro Valley, Arizona took these images of two different features on the the Sun yesterday, overlaying the size of the Earth for reference. Both are viewed in Hydrogen- Alpha light, and the first is a fiery-looking huge prominence from the northwest limb of the Sun. Yikes!

Below, see a comparison of Earth to a current sunspot:

[caption id="attachment_89781" align="aligncenter" width="570" caption="The Earth compared to Sunspot 1312 on 10-10-11. Credit: Ron Cottrell."]

[/caption]

This is sunspot 1312 which has a classic sunspot shape with a core a that's larger than the Earth.

Ron used a 40mm Coronado telescope and a webcam to capture the images. He explains the colors of the Sun in Hydrogen-Alpha, and in particular why the prominence appears fiery red:

"The red color of the prominence is very close to the color collected in the image. The yellow disk is enhanced. I actually capture the disk image in black and white and add the color. I can choose any color. The final image is a composite of two separate images. Prominences are, in general, much fainter than the bright disk. Therefore, the prominence image is captured at a slower shutter speed, e.g. 1/25 sec, compared to the disk image captured at 1/100 sec. The two images are combined in PhotoShop."

You can see more of Ron's handiwork on

his Flickr page.

And speaking of the Sun, activity on our closest star has been ramping up and last week a series of active regions were lined up one after the other across the upper half of the Sun. Interestingly, the Solar Dynamics Observatory was able to capture how these regions twisted and interacted with each other. The video shows activity from Sept. 28 - Oct. 2, 2011, as seen in extreme UV light. The magnetically intense active regions sported coils of arcing loops and numerous times these magnetic field lines above them can be seen connecting with the active region next door. Towards the end of the clip, a leading active region blasted out a coronal mass ejection, quickly succeeded by a blast from another active region. The disruption of the magnetic field from one likely triggered the second, a phenomenon that has been observed before by SDO.

Nancy Atkinson

Nancy Atkinson

Nancy Atkinson is a space journalist and author with a passion for telling the stories of people involved in space exploration and astronomy. She is currently retired from daily writing, but worked at Universe Today for 20 years as a writer and editor. She also contributed articles to The Planetary Society, Ad Astra (National Space Society), New Scientist and many other online outlets.

Her 2019 book, "Eight Years to the Moon: The History of the Apollo Missions,” shares the untold stories of engineers and scientists who worked behind the scenes to make the Apollo program so successful, despite the daunting odds against it. Her first book “Incredible Stories From Space: A Behind-the-Scenes Look at the Missions Changing Our View of the Cosmos” (2016) tells the stories of 37 scientists and engineers that work on several current NASA robotic missions to explore the solar system and beyond.

Nancy is also a NASA/JPL Solar System Ambassador, and through this program, she has the opportunity to share her passion of space and astronomy with children and adults through presentations and programs. Nancy's personal website is nancyatkinson.com