of land on Earth
A team of astronomers at Purdue and the
National Optical Astronomy Observatory have
confirmed a rare discovery of the early
formation of one of the most massive structures
in the present-day universe, a galaxy cluster.
The structure, named PC 217.96+ 32.3A, is
located 12 billion light-years away in the
constellation of Boötes.
“Galaxy clusters are the largest and most
massive structures in the universe comprising
up to thousands of galaxies,” says Kyoung-Soo
Gravity draws matter in the universe together.
Some of this matter combines to form stars, and
a collection of stars forms galaxies. Galaxies, in
turn, can be drawn together into galaxy clusters.
“Galaxy clusters observed in the present-day
universe have the oldest and most massive
galaxies, but their formation process is not well
known,” Lee says. “Protoclusters provide useful
cosmic laboratories where we can directly
witness and study the formation process.”
Lee and Arjun Dey, of the National Optical
Astronomy Observatory, led the team that
confirmed the protocluster using spectroscopic
measurements from the Mayall telescope on Kitt
Peak in southern Arizona and the Keck II
Telescope on Mauna Kea in Hawaii.
A paper detailing the findings of the structure
was published in the Astrophysical Journal.
— Elizabeth K. Gardner
One-sixth of the Earth’s land is highly vulnerable to
invasive species, and most countries have a limited
capacity to protect their natural resources from non-native animals, plants or microbes, a global analysis
Invasive species can spread quickly and dramatically
alter landscapes, ecosystems and human health and
livelihoods, often with harmful consequences.
Researchers from multiple institutions, including
Purdue University, teamed up to create the first
worldwide analysis of invasive species threats,
providing a global-scale outlook on how the
introduction and spread of invasive species could shift
in coming decades as a result of increasing
globalization and climate change. They also assessed
individual nations’ abilities to manage existing invasive
species and respond to new ones, the first country-level evaluation of its kind. The study was published in
The analysis showed that invasive species will
increasingly threaten developing countries and the last
remaining biodiversity hot spots due to increased air
travel to these areas and expansion of agriculture,
factors that can provide opportunity for non-native
species to gain a foothold. This could endanger
livelihoods and food security in already-fragile
economies, says Jeffrey Dukes, study co-author and
Purdue professor of forestry and natural resources and
“You can think of invasive species as biological
pollution — a self-replicating change,” says Dukes, who
is also director of the Purdue Climate Change Research
Center housed in Discovery Park. “It doesn’t take much
effort or intention to bring in an invasive species that
then wreaks havoc on a landscape.”
Areas in most critical need of proactive
management strategies are those with high poverty
levels, rich biodiversity and low historical levels of
Developed countries — which have historically had
both the highest numbers of invasive species and the
strongest management efforts — will continue to face
an onslaught of new invasive species, primarily from
the exotic pet and plant trade and as climate change
disturbs native ecosystems.
— Natalie van Hoose
Jeffrey Dukes, professor of biological sciences and director
of the Purdue Climate Change Research Center.