Astronomy Picture of the Day [1]Discover the cosmos! Each day a different image or photograph of our fascinating universe is featured, along with a brief explanation written by a professional astronomer. 2020 May 1 [2]See Explanation. Clicking on the picture will download the highest resolution version available. A View Toward M106 Image Credit & [3]Copyright: [4]Joonhwa Lee Explanation: Big, bright, beautiful [5]spiral, Messier 106 dominates this cosmic vista. The nearly two degree wide [6]telescopic field of view looks toward the well-trained constellation Canes Venatici, near the handle of the Big Dipper. Also known as NGC 4258, M106 is about 80,000 light-years across and 23.5 million light-years away, the largest member of the [7]Canes II galaxy group. For a far far away galaxy, the distance to M106 is well-known in part because it can be [8]directly measured by tracking this galaxy's remarkable maser, or microwave laser emission. Very rare but naturally occurring, the [9]maser emission is produced by water molecules in molecular clouds orbiting its [10]active galactic nucleus. Another prominent spiral galaxy on the scene, viewed nearly [11]edge-on, is NGC 4217 below and right of M106. The distance to NGC 4217 is much less well-known, estimated to be about 60 million light-years, but the bright [12]spiky stars are in the foreground, well inside our own Milky Way galaxy. Even the existence of galaxies beyond the Milky Way was questioned 100 years ago in [13]astronomy's Great Debate. Experts Debate: [14]How will humanity first discover extraterrestrial life? Tomorrow's picture: light-weekend __________________________________________________________________ [15]< | [16]Archive | [17]Submissions | [18]Index | [19]Search | [20]Calendar | [21]RSS | [22]Education | [23]About APOD | [24]Discuss | [25]> __________________________________________________________________ Authors & editors: [26]Robert Nemiroff ([27]MTU) & [28]Jerry Bonnell ([29]UMCP) NASA Official: Phillip Newman [30]Specific rights apply. [31]NASA Web Privacy Policy and Important Notices A service of: [32]ASD at [33]NASA / [34]GSFC & [35]Michigan Tech. U. References 1. https://apod.nasa.gov/apod/archivepix.html 2. https://apod.nasa.gov/apod/image/2005/M106_ORG4_APOD.jpg 3. http://antwrp.gsfc.nasa.gov/apod/lib/about_apod.html#sraplyy 4. https://blog.naver.com/omololee/221208161212 5. https://apod.nasa.gov/apod/ap130206.html 6. https://blog.naver.com/omololee/221208161212 7. http://www.atlasoftheuniverse.com/galgrps/cvnii.html 8. http://arxiv.org/abs/1307.6031 9. https://en.wikipedia.org/wiki/Astrophysical_maser 10. https://www.spacetelescope.org/news/heic1302/ 11. https://www.spacetelescope.org/images/potw1503a/ 12. https://en.wikipedia.org/wiki/Diffraction_spike 13. https://apod.nasa.gov/debate/debate20.html 14. https://apod.nasa.gov/debate/debate100th.html 15. https://apod.nasa.gov/apod/ap200430.html 16. https://apod.nasa.gov/apod/archivepix.html 17. https://apod.nasa.gov/apod/lib/apsubmit2015.html 18. https://apod.nasa.gov/apod/lib/aptree.html 19. https://antwrp.gsfc.nasa.gov/cgi-bin/apod/apod_search 20. https://apod.nasa.gov/apod/calendar/allyears.html 21. https://apod.nasa.gov/apod.rss 22. https://apod.nasa.gov/apod/lib/edlinks.html 23. https://apod.nasa.gov/apod/lib/about_apod.html 24. http://asterisk.apod.com/discuss_apod.php?date=200501 25. https://apod.nasa.gov/apod/ap200502.html 26. http://www.phy.mtu.edu/faculty/Nemiroff.html 27. http://www.phy.mtu.edu/ 28. https://antwrp.gsfc.nasa.gov/htmltest/jbonnell/www/bonnell.html 29. http://www.astro.umd.edu/ 30. https://apod.nasa.gov/apod/lib/about_apod.html#srapply 31. https://www.nasa.gov/about/highlights/HP_Privacy.html 32. https://astrophysics.gsfc.nasa.gov/ 33. https://www.nasa.gov/ 34. https://www.nasa.gov/centers/goddard/ 35. http://www.mtu.edu/