These distinctive nebular formations are characterised by their axially symmetric, bi-lobed appearance. Many planetary nebulae exhibit this feature, and it is possible that there is a relationship between the two types of nebula, with one preceding the other in their evolution. The exact cause of the bipolar structure is unknown, however it could be linked to bipolar outflow (a process in which a star ejects highly energetic streams of outflow along both poles).
Images from top to bottom:
- The Ant Nebula. Credit: NASA, ESA & the Hubble Heritage Team (STScI/AURA).
- The Homunculus Nebula (left). Credit Nathan Smith (University of California, Berkeley), and NASA.
- The Boomerang Nebula (right). Credit: NASA, ESA and The Hubble Heritage Team (STScI/AURA).
- Minkowski 2-9. Credit: Bruce Balick (University of Washington), Vincent Icke (Leiden University, The Netherlands), Garrelt Mellema (Stockholm University), and NASA/ESA.
- The Hourglass Nebula (left). Credit: NASA, R. Sahai, J. Trauger (JPL), and The WFPC2 Science Team.
- The Eskimo Nebula (right). Credit: NASA, ESA, Andrew Fruchter (STScI), and the ERO team (STScI + ST-ECF).
"If all insects on Earth disappeared, within 50 years all life on Earth would end. If all human beings disappeared from the Earth, within 50 years all forms of life would flourish."
how old is your husband?
He’s 43. And since you’ll probably ask, I’m 29. :)