Ten years ago, the discovery of a planet outside our solar system was considered historic. With advances in technology and space exploration, astronomers have now confirmed the existence of more than 3,000 planets in the universe. Astronomers now know that every star likely has at least one planet orbiting it.

The big question is are there any advanced alien civilizations out there we might talk to? Drake’s equation (1961) included a number of factors–number of stars, fraction that have planets, planets per star orbiting at a distance suitable for water and therefore life, fraction of planets where life likely started, fraction of life-bearing planets on which civilization could emerge, and average life of such a civilization.

Four of these factors remain unknowns, but one thing for sure, the fraction of stars that have planets is now considered close to 100%, and about 20-25% of those planets are in right place for life to evolve over our galaxy’s 13-billion-year life.

In a remarkable editorial written for THE NEW YORK TIMES, Professor Adam Frank ignores the question of whether there’s an advanced civilization out there that could be contacted today. Instead, using Drake’s equation, he asks the question of whether human civilization was the likely the first (or last) in our galaxy. The answer is logically, “no.”

Consider that even if 1 in 10 billion planets (a pessimistic probability) have conditions allowing the rise of an advanced civilization, a trillion civilizations would still appear over the course of our galaxy’s history.

Frank writes, “Given what we now know about the number and orbital positions of the galaxy’s planets, the degree of pessimism required to doubt the existence, at some point in time, of an advanced extraterrestrial civilization borders on the irrational.”

Unfortunately, confirming the existence of such a civilization could take a long, long time.

Want to see a real alien planet? Click here.

It’s Science Tuesday–let’s talk about mosquitoes.

About 20% of people are especially delicious for mosquitoes to take blood from, according to scientists.

* 85% of people secrete a chemical indicating what blood type they have; mosquitoes prefer Type O blood more than Type A and B
* People who exhale more CO2, which attracts mosquitoes from up to 164 feet away (a reason why mosquitoes like to bite pregnant women and larger people)
* Mosquitoes are attracted to body sweat and people with higher body temperatures
* Some skin bacteria attracts mosquitoes; as bacteria are denser on ankles on feet, mosquitoes like to bite there
* Drinking beer attracts mosquitoes (it raises body temperature)
* It’s possible even clothing choices can attract mosquitoes–colors that stand out, as mosquitoes can see you

In contrast, about 15% of people excrete chemicals that appear to repel mosquitoes. Scientists are now attempting to isolate these molecules for potential use in mosquito repellent.

The Smithsonian Magazine has more here.

It’s Science Thursday! This week’s topic: Studies show that reading is good for your brain.

Specifically, they show that reading produces powerful mental imagery and emotions. It’s a form of experience.

Even more, they show that by exposing readers to different people and situations, reading can cultivate empathy, which affects how people see others and relate to them.

One study, for example, showed that children who read HARRY POTTER books and identify with Potter as a character respond to his sympathy for people who are marginalized (e.g., “mudbloods”), leading to them becoming more sympathetic towards corresponding groups in society, such as immigrants and LGBT individuals.

One conclusion is that while reading is good for you, picking more sophisticated reads with more sophisticated characters is even better due to this effect.

Learn more here.