Scientific American - 11.2019

22 Scientific American, November 2019

NASA

ADVANCES

SPACE ARCHAEOLOGY

History

in Orbit

Space junk documents humanity’s

expansion into new frontiers

The word “archaeology” typically brings

to mind crumbling ruins from ancient

civilizations—not gleaming rocket ships

or high-tech spacecraft. But more than

60 years of space missions have scattered

countless artifacts throughout Earth orbit

and across the solar system, creating a his-

toric legacy of exploration for current and

future generations. Alice Gorman, a re -

searcher at Flinders University in Adelaide,

Australia, is one of a few pioneering “space

archaeologists” studying the Space Age.

She is also the author of a new book,

Dr Space Junk vs the Universe: Archaeology

and the Future (MIT Press, 2019).

Scientific AmericAn spoke with Gorman

about assessing the cultural significance of

orbital debris and how to preserve space

artifacts as a heritage for all humankind.

An edited excerpt follows. —Lee Billings

What is “space archaeology?”

Space archaeology uses the physical mate-

rial and the places associated with space

exploration to learn about the human be-

haviors behind them. So this covers infra-

structure on Earth, objects in Earth orbit

and even sites on other worlds. The Apollo

lunar landing areas are good examples—

to me, those are archaeological sites. And

that feeds into the related concept of

“space heritage,” which assigns different

categories of significance—historical, aes-

thetic, social, spiritual and scientific—to

certain artifacts and sites for past, present

or future generations. Much of my work

involves gathering the information to help

make those judgments.

You’re sometimes called Dr. Space

Junk, but I get the sense you don’t

actually like the term.

That’s right. Even though I strongly identify

with that persona, the term “space junk”

is problematic. From an archaeological per-

GEOLOGY

Birth of

the Sahara

Dust on nearby islands hides

secrets of the desert’s origins

The Sahara is the world’s largest and

most legendary subtropical desert, but

knowledge about it is surprisingly limited.

Even estimates of when it formed vary

widely, from more than five million years

ago to mere thousands. Now, however,

geologists studying wind-carried Saharan

dust on the Canary Islands have come

closer to pinning this down: it is, they

report, close to five million years old.

One reason for the uncertainty over

the Sahara’s age is that researchers use

such different methods to estimate it;

these include studying desert dust found

in sediment under the Atlantic Ocean,

analyzing sandstone and modeling the

ancient climate. To help settle things,

geomorphologist Daniel Muhs of the U.S.

Geological Survey (lead author on the

new research) and his colleagues looked

at sediment on Spain’s Fuerteventura and

Gran Canaria islands, where they found

evidence of Saharan dust. The dust ap -

peared in ancient soil layers, whose age

they assessed on the basis of fossils found

in the same layers—and that age agreed

with earlier marine sediment studies.

The researchers reported their finding

in November in Palaeogeography, Palaeo­

climatology, Palaeoecology.

“The conclusion of the study is very

good,” says Zhongshi Zhang, a climate

modeler at the University of Bergen in

Norway, who was not involved in the

work. Because the dust found on the

After two years on the moon, Surveyor 3

has visitors from the Apollo 12 mission.

© 2019 Scientific American

22 Scientific American, November 2019

NASA

ADVANCES

SPACE ARCHAEOLOGY

History

in Orbit

Space junk documents humanity’s

expansion into new frontiers

The word “archaeology” typically brings

to mind crumbling ruins from ancient

civilizations—not gleaming rocket ships

or high-tech spacecraft. But more than

60 years of space missions have scattered

countless artifacts throughout Earth orbit

and across the solar system, creating a his-

toric legacy of exploration for current and

future generations. Alice Gorman, a re -

searcher at Flinders University in Adelaide,

Australia, is one of a few pioneering “space

archaeologists” studying the Space Age.

She is also the author of a new book,

Dr Space Junk vs the Universe: Archaeology

and the Future (MIT Press, 2019).

Scientific AmericAn spoke with Gorman

about assessing the cultural significance of

orbital debris and how to preserve space

artifacts as a heritage for all humankind.

An edited excerpt follows. —Lee Billings

What is “space archaeology?”

Space archaeology uses the physical mate-

rial and the places associated with space

exploration to learn about the human be-

haviors behind them. So this covers infra-

structure on Earth, objects in Earth orbit

and even sites on other worlds. The Apollo

lunar landing areas are good examples—

to me, those are archaeological sites. And

that feeds into the related concept of

“space heritage,” which assigns different

categories of significance—historical, aes-

thetic, social, spiritual and scientific—to

certain artifacts and sites for past, present

or future generations. Much of my work

involves gathering the information to help

make those judgments.

You’re sometimes called Dr. Space

Junk, but I get the sense you don’t

actually like the term.

That’s right. Even though I strongly identify

with that persona, the term “space junk”

is problematic. From an archaeological per-

GEOLOGY

Birth of

the Sahara

Dust on nearby islands hides

secrets of the desert’s origins

The Sahara is the world’s largest and

most legendary subtropical desert, but

knowledge about it is surprisingly limited.

Even estimates of when it formed vary

widely, from more than five million years

ago to mere thousands. Now, however,

geologists studying wind-carried Saharan

dust on the Canary Islands have come

closer to pinning this down: it is, they

report, close to five million years old.

One reason for the uncertainty over

the Sahara’s age is that researchers use

such different methods to estimate it;

these include studying desert dust found

in sediment under the Atlantic Ocean,

analyzing sandstone and modeling the

ancient climate. To help settle things,

geomorphologist Daniel Muhs of the U.S.

Geological Survey (lead author on the

new research) and his colleagues looked

at sediment on Spain’s Fuerteventura and

Gran Canaria islands, where they found

evidence of Saharan dust. The dust ap -

peared in ancient soil layers, whose age

they assessed on the basis of fossils found

in the same layers—and that age agreed

with earlier marine sediment studies.

The researchers reported their finding

in November in Palaeogeography, Palaeo­

climatology, Palaeoecology.

“The conclusion of the study is very

good,” says Zhongshi Zhang, a climate

modeler at the University of Bergen in

Norway, who was not involved in the

work. Because the dust found on the

After two years on the moon, Surveyor 3

has visitors from the Apollo 12 mission.

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