References
Latest References

Best electric toothbrushes for kids 2025
By Joanne Lewsley last updated
Buying Guide These are the best electric toothbrushes for kids, from Oral B Kids and Philips Sonicare for Kids to AutoBrush Sonic Pro.

Vlad the Impaler: The medieval prince who inspired Dracula
By Marc Lallanilla, Callum McKelvie, Jessie Szalay, Kristina Killgrove last updated
Vlad the Impaler was a medieval prince whose bloodthirsty acts inspired the world's most famous vampire, Bram Stoker's Dracula.

Best treadmills 2025: Rack up the miles in the comfort of your own home
By Harry Bullmore, Anna Gora last updated
BUYING GUIDE These are the best treadmills you can buy in every category, from NordicTrack x22i and Mobvoi Home Treadmill to Peloton Tread.

Artemis Program: NASA's plan to send humans back to the moon
By Adam Mann last updated
Basic information about the Artemis program's Space Launch System and Orion capsule.

Genetics: How do we inherit traits from our ancestors?
By Mindy Weisberger published
Discover interesting facts about how traits are passed down over generations through DNA.

50 amazing facial reconstructions, from Stone Age shamans to King Tut
By Christina Hughes last updated
New scientific techniques are helping us reconstruct people from the past in uncanny detail.

Homo erectus: Facts about the first human lineage to leave Africa
By Kristina Killgrove, Joseph Castro last updated
Homo erectus is associated with a number of firsts in its 2 million years of existence, including being the first hominin to travel out of Africa.

Autumn equinox 2025: When does fall begin?
By Sarah Wild last updated
REFERENCE Equinoxes occur twice a year, with night and day being almost the exact same length all across the world. The next equinox is the September fall equinox, beginning on Sept. 22, 2025 in North America.
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