Jump to content
Main menu
Main menu
move to sidebar
hide
Navigation
Main page
Recent changes
Random page
Help about MediaWiki
Special pages
Niidae Wiki
Search
Search
Appearance
Create account
Log in
Personal tools
Create account
Log in
Pages for logged out editors
learn more
Contributions
Talk
Editing
Earth
(section)
Page
Discussion
English
Read
Edit
View history
Tools
Tools
move to sidebar
hide
Actions
Read
Edit
View history
General
What links here
Related changes
Page information
Appearance
move to sidebar
hide
Warning:
You are not logged in. Your IP address will be publicly visible if you make any edits. If you
log in
or
create an account
, your edits will be attributed to your username, along with other benefits.
Anti-spam check. Do
not
fill this in!
== Notes == <!-- List alphabetized. Please keep it that way, thank you! --> {{reflist |30em |group="n" |refs= <ref name="Aoki">The ultimate source of these figures, uses the term "seconds of UT1" instead of "seconds of mean solar time".β{{cite journal |last1=Aoki |first1=S. |title=The new definition of universal time |journal=Astronomy and Astrophysics |year=1982 |volume=105 |issue=2 |pages=359β361 |bibcode=1982A&A...105..359A |last2=Kinoshita |first2=H. |last3=Guinot |first3=B. |last4=Kaplan |first4=G. H. |last5=McCarthy |first5=D. D. |last6=Seidelmann |first6=P. K.}}</ref> <ref name="apsis">aphelion = ''a'' Γ (1 + ''e''); perihelion = ''a'' Γ (1 β ''e''), where ''a'' is the semi-major axis and ''e'' is the eccentricity. The difference between Earth's perihelion and aphelion is 5 million kilometers.β{{cite book|page=144|title=Probing the New Solar System|last1=Wilkinson|first1=John|year= 2009|publisher=CSIRO Publishing|isbn=978-0-643-09949-4}}</ref> <ref name="epoch">All astronomical quantities vary, both [[Secular phenomena|secularly]] and [[Frequency|periodically]]. The quantities given are the values at the instant [[J2000.0]] of the secular variation, ignoring all periodic variations.</ref> <ref name="hill_radius">For Earth, the [[Hill radius]] is <math>R_H = a\left ( \frac{m}{3M} \right )^{\frac{1}{3}}</math>, where ''m'' is the mass of Earth, ''a'' is an astronomical unit, and ''M'' is the mass of the Sun. So the radius in AU is about <math>\left ( \frac{1}{3 \cdot 332,946} \right )^{\frac{1}{3}} = 0.01</math>.</ref> <ref name="jaes41_3_379">Including the [[Somali Plate]], which is being formed out of the African Plate. See: {{cite journal |first=Jean |last=Chorowicz |date=October 2005 |title=The East African rift system |journal=[[Journal of African Earth Sciences]] |volume=43 |issue=1β3 |pages=379β410 |doi=10.1016/j.jafrearsci.2005.07.019 |bibcode=2005JAfES..43..379C}}</ref> <ref name="solar_energy">Aphelion is 103.4% of the distance to perihelion. Due to the inverse square law, the radiation at perihelion is about 106.9% of the energy at aphelion.</ref> <ref name="surfacecover">Due to natural fluctuations, ambiguities surrounding [[Ice shelf|ice shelves]], and mapping conventions for [[vertical datum]]s, exact values for land and ocean coverage are not meaningful. Based on data from the [[Vector Map]] and [http://www.landcover.org/ Global Landcover] {{Webarchive|url=https://web.archive.org/web/20150326085837/http://www.landcover.org/ |date=26 March 2015}} datasets, extreme values for coverage of lakes and streams are 0.6% and 1.0% of Earth's surface. The ice sheets of [[Antarctica]] and [[Greenland]] are counted as land, even though much of the rock that supports them lies below sea level.</ref> <ref name="space_debris">As of 4 January 2018, the United States Strategic Command tracked a total of 18,835 artificial objects, mostly debris. See: {{cite journal |url=https://orbitaldebris.jsc.nasa.gov/quarterly-news/pdfs/odqnv22i1.pdf |title=Satellite Box Score |journal=Orbital Debris Quarterly News |editor1-first=Phillip |editor1-last=Anz-Meador |editor2-first=Debi |editor2-last=Shoots |volume=22 |issue=1 |page=12 |date=February 2018 |access-date=18 April 2018 |archive-date=2 April 2019 |archive-url=https://web.archive.org/web/20190402034308/https://orbitaldebris.jsc.nasa.gov/quarterly-news/pdfs/odqnv22i1.pdf |url-status=live }}</ref> }}
Summary:
Please note that all contributions to Niidae Wiki may be edited, altered, or removed by other contributors. If you do not want your writing to be edited mercilessly, then do not submit it here.
You are also promising us that you wrote this yourself, or copied it from a public domain or similar free resource (see
Encyclopedia:Copyrights
for details).
Do not submit copyrighted work without permission!
Cancel
Editing help
(opens in new window)
Search
Search
Editing
Earth
(section)
Add topic