Solar eclipse: Experts share answers about science, safety, pet reactions

The prospect of a solar eclipse can be intriguing, and on Monday, April 8, much of the United States will have the unusual opportunity to witness a partial or total eclipse, sure to inspire many to gaze directly at the closest star to our planet — though those that choose to do so need to take the proper safety precautions.

Scientific experts at Virginia Tech have answered questions about what makes this solar eclipse so remarkable, what precautions you must take when viewing the eclipse, and what consideration should be given to the pets and other animals who will experience the eclipse with us.

The science of solar eclipses

Nahum Arav, a professor of physics in the College of Science at Virginia Tech, shares perspective about the science behind the solar eclipse.

Q: What is a solar eclipse?

“A solar eclipse occurs when the moon covers part of the sun, known as a partial eclipse, or when the moon covers the entire disk of the sun, known as a total eclipse,” said Virginia Tech astrophysicist Nahum Arav. “When the moon’s orbit puts it directly between the Earth and the sun, the moon casts a shadow on the surface of the Earth. The central part of that shadow, the umbra, is fully shaded, while the outer region, the penumbra, is only partially shaded. Communities that happen to be in the path of the umbra — that is, the path of totality — will see a full eclipse, while those in the penumbra will see a partial eclipse.”

Q: Why are eclipses so rare?

“Solar eclipses happen about twice a year, so they are not that rare. However, most of them are not observed from the United States and most of them are not total. We’ll have to wait until 2045 for the next solar eclipse that crosses a significant portion of the continental U.S.,” Arav said.

Q: What makes this particular eclipse remarkable in Southwest Virginia?

“Viewed from our region, this will be the most the sun will be covered by the moon — 88% — until 2078. The 88% drop in the solar light will be visibly noticeable. Because we are quite close to the path of totality, the sun will resemble a crescent moon during the eclipse. It’s also very important that you only view the eclipse through safe viewing devices,” Arav said.

How to safely view a solar eclipse

Kristofer Rau, a neuroscientist at the Virginia Tech Carilion School of Medicine’s Department of Basic Science Education, offers tips for viewing the solar eclipse with proper safety precautions.

Q: Why is looking at the eclipse potentially harmful?

“Even during an eclipse, the exposed parts of the sun can emit enough light radiation to harm the sensitive parts of your eye,” said Virginia Tech neuroscientist Kristofer Rau. “Photochemical damage may occur when the intense sunlight floods the retina, leading to chemical changes in the eye. Staring at the sun can also cause thermal damage, and literally burn the retinal tissue, which you might not feel because the retina has no pain receptors. If you have ever played with a magnifying glass in the sun, you can appreciate how much light energy can be focused into a small spot.”

Q: What are some of the symptoms of solar eye damage, and what should I do if I experience any of these symptoms?

“Remember that it can take days for symptoms to appear. These can include loss of central vision, a distortion of vision that makes straight lines appear wavy, an alteration of color vision, an increased sensitivity to light, and potentially pain or discomfort in the eyes. If you experience any of these symptoms, you should rest your eyes and give them time to recover in a dimly lit environment. If symptoms do not seem to improve rapidly, you should consult with an eye care professional, such as an ophthalmologist or optometrist,” Rau said.

Q: Can an eclipse ever be viewed without eye protection?

“For those regions of the country that are within the path of totality, where the Moon will entirely block the Sun’s bright surface, there is a very brief amount of time to view the eclipse without the use of eye protection. Unfortunately for the state of Virginia, the magnitude of cover ranges from roughly 80-90% depending on location, so no region will be in the path of totality for this upcoming eclipse. Therefore, if you are in the state of Virginia, you will need to take steps to view the eclipse safely,” Rau said.

Q: If you want to look at the eclipse, what safety devices should you use?

• Eclipse glasses or hand-held viewers: “There are certain chain stores as well as online vendors who sell these glasses and viewers, which are much more powerful than sunglasses. Make sure the glasses and viewers meet the ISO 12312-2 international safety standard.
• Pinhole projectors: “These can be as simple as punching a small hole through an index card, or making a projector with a cardboard box, a white sheet of paper, tape, scissors, and aluminum foil. Just make sure you keep your back to the sun, and observe the eclipse projected on the ground or some other surface. Do not look through the pinhole, directly at the sun.
• Cameras, telescopes, or binoculars with solar filters: “Looking at the sun through an unfiltered camera, telescope, binoculars, or other optical devices can concentrate the solar rays and cause severe damage to the eye. Even very dark ‘polarized’ sunglasses are not safe for looking at the sun because they transmit too much sunlight. These devices must be equipped with a special-purpose filter designed for solar observation,” Rau said.

How pets will react to the eclipse

Mark Freeman, a clinical associate professor with the College of Veterinary Medicine at Virginia Tech, offers advice for how pet owners can prepare their companion animals at home.

Q: A solar eclipse can be exciting for people, but how about for our companion animals?

“The answer to that question is, ‘it depends.’ Most of our pet companions spend much of their time adapting to our schedules and routines,” said Mark Freeman, a cat and dog specialist with the Virginia-Maryland College of Veterinary Medicine. “For those pets, how they react to an eclipse may be tied closely to how we react. If we enjoy it, they probably will too. There are pets, however, who spend a lot of time on their own or in the company of other pets, and these individuals may demonstrate other responses.”

Q: How might pets that don’t readily take cues from humans react?

“For most pets, a transition from daylight to dark is a cue that sleep time is approaching. But the suddenness of an eclipse can be both confusing and alarming. Some pets may seek out their bed, while others may demonstrate anxiety or fear. If you have a pet cat, she may find a place to hide. If you have a pet bird, he may settle in to roost. Your pet dog may become restless and start panting or pacing,” Freeman said.

Q: What can pet owners do to help?

“Some pets will not show any response to a solar eclipse and will go about their normal routine. If your pet is one of these, you won’t have anything to be concerned about. On the other hand, if you have an anxious or nervous pet, or a pet that is most comfortable with a rigid, structured routine, they may benefit from your presence, so you can help them feel safer and more confident by maintaining a calm and quiet attitude with minimal disruptions to your normal routine. Happily, total solar eclipses don’t happen often. But we can find a way to enjoy an eclipse ourselves, while ensuring our pets enjoy it too, or at least are not negatively affected by it,” Freeman said.

Schedule an interview    
To schedule interviews with these experts, contact Mike Allen in the media relations office at mike.allen@vt.edu or 540-400-1700.