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From today's featured article
![Planets of the Solar System](//upload.wikimedia.org/wikipedia/commons/thumb/c/cf/Planet_collage_to_scale.jpg/140px-Planet_collage_to_scale.jpg)
Planets of the Solar System
A
planet
is a large,
rounded
body
that is generally required to be in
orbit
around a
star
,
stellar remnant
or
brown dwarf
. The
Solar System
has eight
(pictured)
: four
terrestrial planets
,
Mercury
,
Venus
,
Earth
and
Mars
; and four
giant planets
,
Jupiter
,
Saturn
,
Uranus
and
Neptune
. The term "planet" at first included the
Sun
,
Moon
and the five planets visible to the naked eye in the sky; they were seen as having associations with the gods.
Copernicus
theorized the Earth was a planet and, like the others, orbited the Sun. "Planet" came to include many objects, such as moons, within and beyond the Solar System. The
International Astronomical Union
in 2006 defined a planet in the Solar System to have
cleared its neighborhood
of other
bodies
, and that extrasolar planets should orbit stars and not be large enough to support
deuterium fusion
. Many planetary scientists, though, still apply the word "planet" more broadly, including
dwarf planets
,
planetary-mass moons
,
rogue planets
and brown dwarfs. (
Full article...
)
Did you know ...
Mencap
video featuring George Webster
In the news
![Iga Świątek and Carlos Alcaraz](//upload.wikimedia.org/wikipedia/commons/thumb/6/62/Iga_%C5%9Awi%C4%85tek_and_Carlos_Alcaraz.jpg/160px-Iga_%C5%9Awi%C4%85tek_and_Carlos_Alcaraz.jpg)
Iga ?wi?tek and Carlos Alcaraz
On this day
June 18
:
Autistic Pride Day
![Cadaver Tomb of René of Chalon](//upload.wikimedia.org/wikipedia/commons/thumb/e/e2/Bar-le-Duc_-_Eglise_Saint-Etienne_-_Le_Transi_-191.jpg/121px-Bar-le-Duc_-_Eglise_Saint-Etienne_-_Le_Transi_-191.jpg)
Cadaver Tomb of Rene of Chalon
- 1898
? The
Cadaver Tomb of Rene of Chalon
(pictured)
in
Bar-le-Duc
, France, was designated a
monument historique
.
- 1958
? English composer
Benjamin Britten
's one-act opera
Noye's Fludde
was premiered at the
Aldeburgh Festival
.
- 1981
? The
Lockheed
F-117
Nighthawk
, the first operational aircraft to be designed around
stealth technology
, made its maiden flight.
- 1994
?
The Troubles
:
Ulster Volunteer Force
members
attacked a crowded bar
in
Loughinisland
, Northern Ireland, with
assault rifles
, killing six people.
- 2009
? The
Lunar Reconnaissance Orbiter
,
NASA
's first mission to the Moon in more than ten years, was launched from
Cape Canaveral
, Florida.
Today's featured picture
|
The
copper sunbird
(
Cinnyris cupreus
) is a species of passerine bird in the family
Nectariniidae
. It is native to tropical Africa, its range extending from Senegal and Guinea in the west to South Sudan and Kenya in the east, and southwards to Angola, Zambia, Zimbabwe and Mozambique. It feeds on nectar that it extracts from selected flowers, such as
Calliandra
spp.,
Leonotis leonurus
,
Syzygium
spp., and
Senegalia polyacantha
. It also takes fruits, spiders and insects, some of which are caught while in flight. This female copper sunbird of the
subspecies
C. c. cupreus
was photographed in a
Persian silk tree
in
Kakum National Park
, Ghana.
Photograph credit:
Charles J. Sharp
|
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