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. 2022 March 16 [2]The featured illustration depicts the entire visible universe and representations of most of the notable objects in it. Please see the explanation for more detailed information. The Observable Universe Illustration Credit & [3]Licence: [4]Wikipedia, [5]Pablo Carlos Budassi Explanation: How far can you see? Everything you can see, and everything you could possibly see, right now, assuming your eyes could detect all types of radiations around you -- is the [6]observable universe. In light, the farthest we can see comes from the [7]cosmic microwave background, a time [8]13.8 billion years ago when the universe was opaque like thick fog. Some [9]neutrinos and [10]gravitational waves that surround us come from even farther out, but humanity does not yet have the technology to detect them. The [11]featured image illustrates the observable universe on an [12]increasingly compact scale, with the [13]Earth and [14]Sun at the center surrounded by [15]our Solar System, [16]nearby stars, [17]nearby galaxies, [18]distant galaxies, [19]filaments of early matter, and the [20]cosmic microwave background. Cosmologists typically assume that our observable [21]universe is just the nearby part of a greater entity known as "the universe" where the same physics applies. However, there are several lines of popular but speculative reasoning that [22]assert that even our universe is part of a [23]greater multiverse where either different physical constants occur, [24]different physical laws apply, [25]higher dimensions operate, or slightly [26]different-by-chance versions of our standard universe exist. Available: [27]High res image version with readable annotations | [28]Clickable annotation version Tomorrow's picture: open space __________________________________________________________________ [29]< | [30]Archive | [31]Submissions | [32]Index | [33]Search | [34]Calendar | [35]RSS | [36]Education | [37]About APOD | [38]Discuss | [39]> __________________________________________________________________ Authors & editors: [40]Robert Nemiroff ([41]MTU) & [42]Jerry Bonnell ([43]UMCP) NASA Official: Phillip Newman [44]Specific rights apply. [45]NASA Web Privacy Policy and Important Notices A service of: [46]ASD at [47]NASA / [48]GSFC & [49]Michigan Tech. U. References 1. https://apod.nasa.gov/apod/archivepix.html 2. https://apod.nasa.gov/apod/image/2203/VisUni_WikiBudassi_2400.jpg 3. https://creativecommons.org/licenses/by-sa/4.0/deed.en 4. https://commons.wikimedia.org/wiki/File:Extended_universe_logarithmic_illustration_(English_annotated).png 5. https://commons.wikimedia.org/wiki/User:Unmismoobjetivo 6. https://en.wikipedia.org/wiki/Observable_universe 7. https://wmap.gsfc.nasa.gov/universe/bb_tests_cmb.html 8. https://en.wikipedia.org/wiki/Age_of_the_universe 9. https://icecube.wisc.edu/outreach/neutrinos/ 10. https://www.ligo.caltech.edu/page/what-are-gw 11. https://commons.wikimedia.org/wiki/File:Extended_universe_logarithmic_illustration_(English_annotated).png 12. https://en.wikipedia.org/wiki/Logarithmic_scale 13. https://solarsystem.nasa.gov/planets/earth/overview/ 14. https://solarsystem.nasa.gov/solar-system/sun/in-depth/ 15. https://solarsystem.nasa.gov/solar-system/our-solar-system/in-depth/ 16. http://www.atlasoftheuniverse.com/12lys.html 17. https://apod.nasa.gov/apod/ap110614.html 18. https://apod.nasa.gov/apod/ap180305.html 19. https://apod.nasa.gov/apod/ap140512.html 20. https://apod.nasa.gov/apod/ap130325.html 21. https://science.nasa.gov/astrophysics/big-questions/How-do-matter-energy-space-and-time-behave-under-the-extraordinarily-diverse-conditions-of-the-cosmos 22. http://asterisk.apod.com/viewtopic.php?f=39&t=21958 23. https://en.wikipedia.org/wiki/Multiverse 24. https://medium.com/starts-with-a-bang/ask-ethan-96-is-the-multiverse-science-ecceb24fa2af 25. http://www.pbs.org/wgbh/nova/blogs/physics/2014/04/how-many-dimensions-does-the-universe-really-have/ 26. https://apod.nasa.gov/apod/ap170401.html 27. https://apod.nasa.gov/apod/image/2203/VisUni_WikiBudassi_2400.jpg 28. https://commons.wikimedia.org/wiki/File:Extended_universe_logarithmic_illustration_(English_annotated).png 29. https://apod.nasa.gov/apod/ap220315.html 30. https://apod.nasa.gov/apod/archivepix.html 31. https://apod.nasa.gov/apod/lib/apsubmit2015.html 32. https://apod.nasa.gov/apod/lib/aptree.html 33. https://antwrp.gsfc.nasa.gov/cgi-bin/apod/apod_search 34. https://apod.nasa.gov/apod/calendar/allyears.html 35. https://apod.nasa.gov/apod.rss 36. https://apod.nasa.gov/apod/lib/edlinks.html 37. https://apod.nasa.gov/apod/lib/about_apod.html 38. http://asterisk.apod.com/discuss_apod.php?date=220316 39. https://apod.nasa.gov/apod/ap220317.html 40. http://www.phy.mtu.edu/faculty/Nemiroff.html 41. http://www.phy.mtu.edu/ 42. https://antwrp.gsfc.nasa.gov/htmltest/jbonnell/www/bonnell.html 43. http://www.astro.umd.edu/ 44. https://apod.nasa.gov/apod/lib/about_apod.html#srapply 45. https://www.nasa.gov/about/highlights/HP_Privacy.html 46. https://astrophysics.gsfc.nasa.gov/ 47. https://www.nasa.gov/ 48. https://www.nasa.gov/centers/goddard/ 49. http://www.mtu.edu/