10 July: Scientists report that the
Moon formed
slightly later than thought (4.425 ±0.025 bya) and that it hosted an
ocean of magma
for much longer than previously thought (~200 My).
[
42
]
Image: the thermal state
of the Moon
at age 100 My (from the study)
15 July: In two studies of the
Global Carbon Project
researchers summarise and analyse new estimates of the
global methane budget
and provide data and insights on sources and sinks for the geographical regions and economic sectors where the rising anthropogenic methane emissions have changed the most over recent decades.
[
55
]
5 August: The flora of New Guinea - long known the "Last Botanical Frontier" - is thoroughly cataloged by researchers for the first time.
Bulbophyllum
is the most diverse plant genus in
New Guinea
with 658 native species, 91% of them endemic.
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118
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13 August: Melting of the
Greenland ice sheet
is shown to have passed the point of no return, based on 40 years of satellite data. The switch to a dynamic state of sustained mass loss resulted from widespread retreat in 2000–2005.
[
147
]
16 December: Chinese
Chang'e 5
spacecraft return the first lunar sample since 1976.
[
579
]
18 December: News reports about the detection of candidate ETI radio signal,
BLC1
, apparently from the direction of
Proxima Centauri
, the closest star to the Sun.
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583
]