Lacus Felicitatis

{{Short description|Surface feature on the Moon}}

File:Posidonius-Agrippa Si - Aldo Ferruggia.jpg

{{Infobox Lunar mare

|name = Lacus Felicitatis

|image = Lacus-felicitatis-clem1.jpg

|caption =

|coordinates = {{coord|18.5|N|5.4|E|globe:moon_type:landmark|display=inline,title}}

|diameter = 98 km

|eponym =

}}

Lacus Felicitatis (Latin fēlīcitātis, "Lake of Happiness"){{gpn|3207}} is a small patch of the lunar surface that has been inundated by flows of lava, leaving a level patch with a lower albedo than the surrounding ground. It is located in Terra Nivium, an area of continental ground to the north of the Mare Vaporum. About 70–80 km to the northeast of this area are the Montes Haemus, along the southwestern edge of the Mare Serenitatis.

The selenographic coordinates of the centre of Lacus Felicitatis are 18.5° N, 5.4° E, and it has a maximum extent of 98 km. In outline it has a bent shape, with a wing to the northwest and another to the east. The border is somewhat uneven, and it is surrounded by rugged lunar surface.

Three tiny craters within this formation have been assigned names by the IAU. These are listed below.

class="wikitable" ! Crater ! Coordinates ! Diameter ! Name source

Dag |18.7° N, 5.3° E |align="right"|0.5 km |Scandinavian masculine name

Ina |18.6° N, 5.3° E |align="right"|3 km |Latin feminine name

Osama |18.6° N, 5.2° E |align="right"|0.5 km |Arabic masculine name

Ina is a semi-circular depression that is only about 30 m deep and is difficult to image from the Earth.

In November 2006, it was suggested that Ina was the result of a gas eruption in the last 10 million years.{{Cite web |last=Philips |first=Tony |date=2006-11-09 |title=Is the Moon Still Alive? |url=http://science.nasa.gov/science-news/science-at-nasa/2006/09nov_moonalive/ |archive-url=https://web.archive.org/web/20150419104929/http://science.nasa.gov/science-news/science-at-nasa/2006/09nov_moonalive/ |archive-date=2015-04-19 |access-date=2007-04-20 |publisher=NASA }}{{Cite journal |last1=Schultz |first1=Peter H. |last2=Staid |first2=Matthew I. |last3=Pieters |first3=Carlé M. |date=2006 |title=Lunar activity from recent gas release |url=http://www.nature.com/nature/journal/v444/n7116/abs/nature05303.html |journal=Nature |volume=444 |issue=7116 |pages=184–186 |bibcode=2006Natur.444..184S |doi=10.1038/nature05303 |pmid=17093445 |issn=1476-4687|url-access=subscription }}

Image:Ina hrp219a.jpg Mapping camera image of Ina (center)]]

Image:Lunar crater Ina false color.jpg